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Prior Skills Needed: Students must know: there are 60 minutes in an hour, their ten combinations, and how to count by tens and hundreds.

Further they will need to know or be taught how to use a number line to solve difference (subtraction) problems which I will explain here.

To solve the problem 13-7, a student draws a line and writes 13 on the far right and 7 on the far left. From 7, the student draws line jumps to make 10, so the first jump is +3 to get to 10. The next jump the student wants to get to 13 so the final jump would be +3. Adding the two jumps, 3+3 is 6, which is the answer.

Here’s another 63-28. Draw a line with 63 on the far right and 28 on the far left. Starting at 28, make a 10 by adding 2. So, the first jump is +2 which brings you to 30. Second, count by tens. You are at 30 so you jump to 60 which is +30. Finally, the last jump is +3 ones to get to 63. Add the jumps together, 2+30+3, so the answer to the problem is 35.

Lastly, let’s add 100′s into the mix. Try your hand at 230-119. Draw your line, 230 on the right, 119 on the left. Start on the left, jump to the next 10 (+1 to 120). Jump to the next 100 you want (+100 to 220). Jump to the next 10 you want (+10 to 230). If there were ones, you might have to do a last jump. Add the jumps (+1+100+10=111). Your answer is 111.

Now, try elapsed time using the same method. Let’s solve the following story problem together:

Luìs got on the bus for a classroom astronomy field trip to the Observatory at 1:35p.m. After studying several charts of galaxies and nebulae inside and viewing Saturn’s rings through the telescopes outdoors, Luìs and his class got back on the bus and headed back to school. They arrived 2 minutes late at 5:02p.m. and got to have a pizza party before going home. How much time in-between when Luìs got on the bus at 1:35p.m. and when he arrived back at school at 5:02p.m.?

Draw a line. Write 5:02 on the far right side and 1:35 on the far left side. Start from 1:35 and jump to the next 10. (+5mins. to 1:40). Next, jump to the next hour, just remember that you’re not making 100 but 60 since there are 60 minutes in an hour, so instead of adding 40 and 60 to make 100, you want to add 40 and 20 to make 60 (+20mins. to 2:00). Next, jump by 1′s to the hour you want, be sure to label it in hours (+3hrs. to 5:00). Finally jump the remaining minutes (+2mins. to 5:02). Add up all your jumps (5mins + 20mins. + 3hrs. + 2mins.) Add the minutes and hours separately. You should get 3hrs. and 27mins. as your answer. Notice that you can challenge students to combine the first two steps in to one step and jump straight from 1:35 to the next 60 combination (35+25=60) which can be slightly more challenging. You may also present a problem where the minutes add up to larger than 60 and students will need to convert minutes to hours adding yet another level of challenge. Try several more on your own!

Did you notice how much detail I wrote into this story problem? Besides learning a new skill, the story part of the math problem is developed to engage the student’s sense of curiosity (using the astronomy vocabulary), their sense of meaning (class trip), and appeal to their sense of fun (pizza party). The student is likely excited and engaged and may want to discuss their recent trip or how much they love pizza or what they know about astronomy. STOP! Don’t tell them to be quiet and focus! (This will just make them focus on how they didn’t get to share their story). Let them talk, just give them some parameters. This is great discussion to warm up students’ brains and get them intrinsically motivated and excited to solve this problem. Tell them you will give them 2 minutes to talk to a friend or neighbor about how they can each relate to this problem. They may want to try more and more elapsed time problems and even make up their own stories!

Welcome to my math tutoring website. Here you can find information on my hourly rates, current availability, and my teaching approach as well as a variety of blogs and resources related to math teaching and learning.

I am available to tutor children from Kindergarten through 8th grade to help develop good number sense, mental math abilities, knowing multiple story problem solving strategies, fraction number sense, fraction/decimal/percent computation, build square and triangle numbers, write and compute with exponents and square roots, algebraic relationships, solving for an unknown, balancing equations, building 3 dimensional shapes and finding their volumes, thoroughly understand and convert the metric and U.S. Customary Units during measurement practices, solving logic problems, and reading biographies of famous mathematicians. All this helps to develop your child’s confidence in her or his own self and the ability to problem solve and think logically and mathematically

I can also can help you brush up on the areas of math that you never quite got down in school as a kid.  Do fractions frustrate you? I can help you understand them inside and out in just an hour or two. Does 300 kilometers, 14 degrees celsius, 27 millimeters and 22 kilograms just get weird sometimes? I can help you because I’ve been there myself and believe me, you will feel more confident in your own life.

Email me at: tiatia@gmail.com

Several of my friends recently have been asking me if I know anything about Kumon, an international math and reading center. Parents have legitimate cause for concern as math scores in the U.S. rank considerably lower than other leading nations as well as the Baltic States and the Russian Federation. A New York Times article from last Fall observes that U.S. math scores have plateaued since the Federal Government and No Child Left Behind laws have trumped state standards in education. I did not know much about Kumon so I looked into it.

The Internet has some good information about what Kumon is and how it is different from other learning centers. Kumon was started 50 years ago by Toru Kumon, a Japanese father who wanted to help his son. His innovative techniques helped his son so much that he was doing calculus by the time he was in 6th grade. You can watch a video ad here. Kumon is a self-paced learning method designed to create a strong foundation in numeration and instill self-motivation and a life-long desire for learning.
I was still curious about what these centers looked like, what the worksheets look like and the general feel of the place. I found on Google Maps that Portland has four different Kumon Learning Centers. I made an appointment with the one closest to me in SE Portland. When I arrived, Taek Soo, who proudly owns four of the ten Portland franchises, met with me, gave me some literature, and set up a short video for me to watch. At Kumon, he explained, students move through daily worksheets in small, incremental steps. When they have sufficiently mastered one area by passing a test, they may move on to the next area. Kumon students come into the center twice a week to have the instructor check their work, answer questions and give the student the next packet. Parents play an essential role keeping students working on their daily “Kumon Time.”

The environment was clean, comfortable and quiet music was playing in the background. Taek Soo, whose educational background is in engineering, and who has run the Portland Kumon Centers for 16 years, was extremely generous with his time and willing to answer all the questions I had. He even let me take the placement test. Given the time limit of 25 minutes, I feel ashamed to say that I wasn’t able to finish the test within these parameters. I found my computation skills to be sluggish and forgot various short cuts I once knew. Taek Soo did however compliment me on my fraction skills. I found myself so intrigued by Kumon that I decided to sign up for the month of June to try it out for myself. The monthly tuition is $100 plus a one-time $50 sign-up fee. The price is cheaper than a professional development class, though I won’t get any credits for it. The curriculum at Kumon goes all the way through calculus as well as offering additional courses in statistics and engineering math. I am fascinated to see how it will go and look forward to sharing my experience with my readers.

After submitting its proposal in January for Race To The Top funding, the state of Oregon soon learned its proposal fell short of its goal. Quite a bit short. Oregon was not one of the 16 finalists. In fact, its proposal ranked 7th worst in the nation of states which submitted proposals because two essential pieces were missing, participation from local teacher’s unions and actual reform.

President Obama and Secretary of Education Duncan made it clear they were looking for cohesiveness and collaboration in state proposals. Proposals by Delaware and Tennessee, the only two states to win in the first round, elicited broad support and collaboration by teachers and teacher unions. Compare 93% of teacher unions in Tennessee signing on to their state proposal, to fewer than 39% of Oregon’s teacher unions. (edweek.org)

Why didn’t they sign on? The Portland Teachers Union (as well as Eugene and Beaverton) didn’t sign on to Oregon’s proposal because turning around the lowest 5% of schools can only be done one of four ways according to federal law: cutting half the staff and administrators, closing the school and re-opening as a charter school, closing the school permanently, or link teacher evaluations directly to student results.

The Portland Teachers Union disagrees with these as the only possible ways to improve failing schools. The planning team assigned by Governor Kulongoski to design the content of the proposal included many credible organizations. It failed, however, to include teacher unions, student organizations or PTA groups. I find myself asking the question: Who has the best interests of our children’s education closest to their hearts, Nike (on the planning team) or the student’s parents and teachers?

In addition to inadequate support, Oregon’s proposal does not address innovative reform, rather it focuses on current best practices and how to improve and enhance them. Not to say that this wouldn’t be the best way forward for Oregon but it certainly isn’t what Secretary Duncan and his secret team of judges were looking for. The proposal flaunts a heavy load of data to sift through and brags about all the current programs, assessments, curriculum and tests that it already uses. It throws around acronyms for these programs without delving into the underlying purposes of the programs, thereby eliminating any option to pursue other programs that might better suit Oregon student needs now or in the future. It discusses in theory all the wonderful improvements it will make to instruction, teachers, graduation rates, etc., without including a detailed and concrete plan of action, though admittedly no state was given adequate time to plan details. The proposal projects that receiving funding will increase student improvement by only 2%-6%. That doesn’t seem like a lot.

In summary, rather than innovative reform, Governor Kulongoski’s exclusive team proposes more of the same. For phase 2, everyone must be on board at every stage of the game or Oregon should not pursue the funding at all.


If you would like to make math more fun for your child put this portable math pack together and take it with you on your next outing. All you need are three dice, a pack of cards, a calculator, 50-100 pennies (or something for counting), a big piece of sidewalk chalk, string, paper, a compass (the mathematical kind), a ruler and a pencil. Gather these items and put them together in a lunchbox, pencil box, or any kind of portable carrying case. Then, print out these game ideas and add them to the box for fun learning on the go. There are many more ideas online.
Dice Games: roll 2-3 dice and add the numbers, roll 2 dice and subtract, roll 3 dice and add two and subtract the third, roll 2 dice and multiple, roll 3 dice and add two and then multiply the third, roll 3 dice and multiple all the dice in at least two different ways, identify even and odd numbers rolled, take turns rolling three dice and add, subtract, multiply or divide to get as close to ten as possible, roll one die as many times as you want to get as close to 21 as possible without going over and the person who is the closest wins, each player (2, 3, or 6 players) gets 10 pennies and is assigned a number 1-6 (or multiple numbers like 1 & 2, or 1,2, & 3, depending on the number of players) then each player takes turns rolling three dice- if a one is rolled for example the player whose number is one may put a penny in the center- the player to get rid of all 10 pennies first is the winner.
Card Games: Play Go Fish (seven cards each) and make pairs, play “war” whoever has the high card wins, play “peace” whoever has the low card wins, put down two cards and add, subtract or multiply them as quickly as you can, with three players- two draw a card and without looking at them place them face out on their forehead- the third person names the product and the two with cards must guess what their card is as quickly as possible, play “fish plus one” (first remove the face cards) where instead of looking for exact matches you want to find the match to your card plus one (if you have a 5 you want to ask for a 6 because 5+1=6), play “fish plus two, three, four or five”, play “fish plus plus” where you try to accumulate a set of three cards where two add up to the third and then you can lay them down (2+4=8), play “Build-a-Number” where a card placed on the table can be built on with two other cards to create a number set (for example if an 8 is placed on the table, you could place a 6 & 2 down or two 4′s or a 5 & 3 but you could also put down a 1&9 using the 8 for part of the building rather than the sum)- in addition to building a sum you can also build a product.
Mental Math: The idea behind mental math is to help kids be flexible thinkers and to visualize numbers and object in their heads. It also gives them practice in composing and decomposing numbers. Here are some examples: There are 4 cars, 2 bicycles and 1 tricycle, how many wheels in all? There are 12 hungry kids who will eat three pieces of pizza each. Each pizza has 8 slices. How many pizzas do they need? Will there be any leftovers? It is the 4th of March, how many more days until the 17th of March? After some practice you will get very good at making these up on the spot.
Calculator: use a calculator to check answers, to play, to add prices at the grocery store, to find percentages, decimals, miles, times and more. Pick a number (say, 18) and add it to the palindrome of that number (81) and see your results- try this with several numbers and find a pattern (make sure you try with 3 digit numbers and higher as well), play “broken calculator,” try to get a certain number to appear on the calculator screen (say 96) without actually pressing either 9 or 6- you can use any operation necessary, find the numbers that look like words when you turn the calculator upside down (07734=hello) and come up with a math problem or riddle to get 07734 (or whatever your word is) as your answer- then show it off).
Compass, ruler, pencil, paper: Challenge yourself to create different shapes, angles, lines with only these tools. For example, can you make a hexagon? Can you make a 90 degree angle? Can you accurately make a shape inside another shape- a circle inside a triangle for example? Measure and compare objects with your ruler, find a stick or use your pencil and attach the string to it on one end and the sidewalk chalk to it on the other end- draw a large circle outside on the sidewalk in chalk then make up some games to play.
Have fun exploring mathematics every day!

Mathematics curriculum in elementary grades must include much more than teaching the four operations and isolated units on fractions, decimals, percentages, and geometry. The greatest challenge is that many teachers of K-5 do not themselves have a strong foundation in math because their teachers in turn did not. It is time to break that cycle and seek out new understandings in mathematics and learn how intricately connected are these isolated math subjects.

The Portland Public School District currently adopts Investigations in Number, Data, and Space for its K-5 graders and Connected Mathematics 2 for its 6-8 graders. While there is much controversy surrounding the benefits and detriments of various mathematics curricula, the focus of this article is how teachers, parents, board members, tutors and other educators of Portland’s children can best prepare elementary students for algebraic success in middle school and beyond. The National Council of Teachers of Mathematics’ (NCTM) reported recently that overall, high school students are not achieving adequate levels of success in algebra. As a result there is a push for improving algebraic instruction at the middle school level. I further assert that algebraic concepts can and should be addressed at the elementary school level. NCTM lists four Pre-K-12 algebraic understandings, that students:

  1. Understand patterns, relations, and functions
  2. Represent and analyze mathematical situations and structures using algebraic symbols
  3. Use mathematical models to represent and understand quantitative relationships
  4. Analyze change in various contexts
The Connected Mathematics 2 website from Pearson Publications states about algebra that “variables are not letters that stand for unknown numbers. Rather they are quantitative attributes of objects, patterns, or situations that change in response to change in other quantities.” Algebraic skills addressed and emphasized in the Connected Math 2 curriculum include the following skills and understandings gleaned from their website, that students:
  1. Represent and interpret graphs
  2. Understand and use the commutative, distributive and inverse properties
  3. Understand and use exponential relationships
  4. Develop rules, procedures and formulas
  5. Estimate and judge accuracy of answers, provide proof of reasonable solutions
  6. Find missing factors and addends
  7. Understand relationships among variables
One important concept to focus on in the elementary classrooms to develop algebraic reasoning, is the mathematics of change. Teachers can use growth and change in plants, pattern blocks, or similar tools to help students learn about constants and variables, observe how the variables change, discover the pattern of change, represent and analyze those patterns. Growth problems can also teach exponential relationships. Teachers should often use missing addends that are not at the end of the equal sign in teaching the four operations. For example, x 8 = 32. This will help students understand inverse properties, how division and multiplication are related as well as addition and subtraction. Constructing and deconstructing two and three digit numbers helps students understand commutative and distributive properties. Mental math problems in 2-5 minute increments are a great use of stagnant time in school and encourage children to be quick thinkers and adroit problem solvers. Using a scale for weighing objects will help younger students better understand equalities. Teachers should be sure to use weights and other forms of  measurements, then have students write out the equalities in an equation (2 blue Legos=5 yellow Legos, 1g + 1g + 1g = 3g) Using multiple numbers on each side of an equation will help children understand the concept of equalities. For example 17-5=6+6 (True or False?). Also use missing addends such as 3x=14+7. When teaching fractions, decimals and percentages, teachers can use ratios and equivalent fractions to further aid students in understanding relationships among variables. An important concept is to understand that a number can be equal to another number that does not look the same. For example: 3/9=1/3. Students should understand this on a conceptual level with the help visual aids such as pattern blocks, Cuisinart rods, or similar tools, rather than memorizing the rules on how to find the greatest common factor.

What I read:
http://blogs.edweek.org/edweek/campaign-k-12/2010/03/xx_states_are_named_race_to_th.html

Fifteen states plus Washington DC, out of 25 state applicants have made the cut and will now send a team to Washington the week of March 15th, to make presentations. The finalists are:

Colorado, Delaware, the District of Columbia, Florida, Georgia, Illinois, Kentucky, Louisiana, Massachusetts, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, and Tennessee.

Winners will be announced in April.

What I read
From Science Daily:
“Friends’ School Achievement Influences High School Girls’ Interest in Math”

“Few Gender Differences in Math Abilities, Worldwide Study Finds”
“Believing Stereotype Undermines Girls’ Math Performance: Elementary School Women Teachers Transfer Their Fear of Doing Math to Girls, Study Finds”

From the MathForum:
“Girls’ Attitudes, Self-Expectations and Performances in Math”

From the News Bureau in Illinois:
“Girls’ Confidence in Math Dampened by Parents’ Gender Stereotypes”

From Prufrock Press Inc:
“Helping Teachers to Encourage Talented Girls in Mathematics”

There is a widespread belief in our country that only certain people have the talent to pursue mathematics-related careers and to take advanced math classes. This belief tends to assume that males and Asians are more talented in math than are females and non-Asians. While innate talent is a widely disputed subject, the fact is that if there are some people born with an innate genius in math, those are very few. What matters most is effort, persistence and confidence. It’s time to start letting students in on this “secret” of math.

There are many articles and studies trying to understand when the majority of girls get turned off to mathematics (and science, computers and technology) and how to turn that around. The most apparent issue that came out several times when reading the above articles, is that girls tend to have less confidence in their abilities to do math. When I attempt to track this backwards, it seems that the low confidence is directly connected to math anxiety which stems from two barriers: societal influences and the competitiveness of the math environment.

Let’s talk about the first barrier, societal influences. Girls tend to tune in to their environment and the people in their environment to obtain information about how to act and think. If parents and/or teachers think that boys have a higher aptitude for math, that information is communicated through body language, verbal cues, facial expression, assumptions of girls’ abilities and persistence, and unsolicited help. When adults try to “help” female students with their math, they are often really hurting girls’ confidence in their own abilities. So, note to parents and teachers, lay off the helping and encourage all your students, especially girls to persist in finding their own answers without your help. Another major societal influence for girls are their peers. Girls like to do things together in pairs or groups. If all their friends are going to take an art class instead of an advanced algebra class, which class do you suppose she will choose? The adults in girls’ lives must encourage them to pursue mathematics despite what their peers are choosing. Part of this encouragement is believing in their abilities and having high expectations that they can and will succeed.

The second barrier to girls’ positive attitudes towards mathematics is the competitive environment of the math class. Math classes tend to held in a competitive and fast-paced environment. There is little think time and little opportunity for small group or cooperative learning. While some girls thrive in this competitive math environment, the majority of girls get turned off by needing to come up with answers and solutions to problems as quickly as possible and not having the opportunity to check in with their peers before they decide on a solution. Girls “need classrooms in which they will be heard and understood and where they can discuss ideas before coming to conclusions” (Gavin & Reis-Prufrock Press).

Teachers should do their best to create an environment in the math class that

  1. Offers choice between competitive and cooperative work
  2. Allows think-time (using think-pair-share or journaling) and disallows shout-outs
  3. Encourages risk-taking
  4. Includes cross-curricular activities such as math and writing, dance or music
  5. Uses assessments such as math portfolios and projects in addition or instead of traditional tests
  6. Uses open-ended questions on tests instead of multiple choice
  7. Doesn’t give unsolicited help, instead encourage students to persist in finding their own solutions
  8. Provides some single-sex learning opportunities
  9. Uses co-ed small groups but single sex pairing (since girls tend to defer to boys in partner math situations)
  10. Holds Family Math Nights planned and carried out by girls (boys should get this opportunity as well)
  11. Gives girls the opportunity to tutor younger children and organize math clubs
  12. Ensures math topics are of interest to girls as well as boys (not just sports and construction but also paper folding, spread of diseases, endangered species, scale drawings and patterns)
  13. Uses a challenging curriculum that introduces different number systems, Fibonacci numbers, non-euclidean geometry, fractals, chaos theory and other such topics in mathematics
  14. Introduces knowledge of female mathematicians such as Hypatia, Marie Agnesi, Sophie Germain, Evelyn Boyd Granville, Sonya Kovalevskaya, and Mary Somerville.

Teacher Resource
Math Publication Best Sellers from Prufrock Press

What I read
Chapter 10 of Elementary and Middle School Mathematics

Part 2 in developing meanings for the operations focuses on multiplication and division, what strategies children use, what types of modeling a teacher should use and how the teacher’s understanding of approaches can enrich students’ understanding.

Multiplication and division can both be learned as early as 1st grade. Sound ridiculous? Not if you understand the relationships between all the properties. For example, when teaching multiplication to children, one of the most used approaches is to show how multiplication is merely repeated addition. For example: Eduardo grew 8 tomato plants. Each tomato plant produced exactly 5 tomatoes each. How many tomatoes will Eduardo harvest? The problem boils down to 8 x 5. There are 8 equal groups of 5 sets. The first factor (number) counts how many parts or sets. The second factor tells the size of each set or part and is also known as the multiplicand. In order to solve this problem using repeated addition, you create 8 groups of objects with 5 objects in each group. The resulting equation: 5+5+5+5+5+5+5+5 = 40 should be written down by the student as well as 8 x 5 = 40 next to it. Students will begin to learn the relationship. Equal group problems may also be considered as rate problems.

The major conceptual hurdle to developing meaning for multiplication and division is understanding groups of things as single entities and also that each group has individual objects. Once this mental obstacle is conquered, children of just about any age can begin working with these operations.

Van De Walle talks about four classes of “multiplicative structure,” and that there are two used most often in teaching multiplication. The first is equal groups, which I have written about already. The second class is multiplicative comparison. There are some fantastic example problems of both types that Van De Walle includes in his book. Comparison problems usually compare two people who have two different amounts of something. For example, Trudy built 5 models during art class. Her friend Clarissa built 3 times as many models as Trudy. How many models did Clarissa build?

Consider the two multiplication examples I have given here. Figuring out how to solve each one requires a slightly different way of thinking and certainly a different strategy. Compare this type of thinking to solving a page of textbook multiplication problems. You will be developing meanings for multiplication, not just how to get the right answer. Understanding these meanings are a foundation for algebra as well as other types of advanced mathematics. Van De Walle suggests each math lesson should include 2-3 problems that allow students to use any technique and any math tool they like. For each problem they solve, they must explain, preferably in writing and then later in a discussion, how they solved each problem. Van De Walle also includes a great activity for finding factors in this book, assigning numbers to students and having them use counters, arrays, etc. and then write two equations, an addition and a multiplication for each factor.

Remember how multiplication and addition have a special relationship via repeated addition? A similar relationship occurs between division and subtraction. Division is repeated subtraction. For example, the problem 24/6 = 24-6-6-6-6. A hundreds chart is a useful tool for solving these problems and helping your students skip count backwards as well as forwards will help them use this strategy more efficiently. Other helpful models for practice are counters, number lines and arrays.

When teaching division, teach it at the same time as multiplication or very soon after so students may practice both types of problems and begin to see their relationships. Avoid using the term “goes into,” which carries very little meaning, and instead use “divided by.” Additionally, don’t be afraid of large numbers. Since the strategies and understanding of products and quotients are the same for small vs. large quantities, solve  2 x 4, 13 x 11, and 102 x 15, 6/3, 24/8, 200/5 and even much larger numbers should be introduced at once. To help students see the relationship between multiplication and division, think about how you will word each problem. For example, asking “6 times what is 24?” is more effective than asking “24 divided by 6 is what?”

A note on remainders. There are two methods for remainders in division problems. Method 1 is to leave the remainder as a quantity left over (i.e. 16 R1). Method 2 is to partition the remainder into fractions (i.e. 16 1/16). Van De Walle prefers method 2. In real contexts, you sometimes need a whole number answer so you must round up or down. In a problem where a certain number of cars are needed to transport students for example, using a fraction or remainder answer is useless. There are three ways to decide whether to round the number up of down. If you discard the remaining amount (nobody gets the leftover jellybean) you round the number down. A forced amount (you need an entire car for the one extra student) you must round up. A rounded number will go up or down depending on whether the remaining amount is greater or less than five (We will need 9.6, or about 10 hours to build a compost container).

Finally, when you write or re-write problems for your classroom, make up problems with different contexts. Instead of just using objects such as brownies or pencils. Be sure to use problems that use length, time and volume.

Teacher Resource
Book: Knowing and Teaching Elementary Mathematics: Teacher’s Understanding of Fundamental Mathematics in China and the United States
This book by Liping Ma was highly recommended to me. I have not read it but thought I would pass it on to you. Let me know by posting a comment, if you have read this book and what you think of it. Ma defends the belief that children need to know both arithmetic as well as theory for solid mathematical thinking. Read the editorial review on Amazon by clicking on the book link above or click here.

What I read
Chapter 10 of Elementary and Middle School Mathematics

Part 1 is a synopsis of Chapter 10 of John A. Van de Walle’s book, how to help children develop an understanding for the meanings of addition & subtraction and how they relate. Part 2 will discuss multiplication & division.

There are two main methods for teaching addition and subtraction. The first method is to use contextual problems. The second method is to use multiple models such as counters, drawings and number lines. Using these two methods will help children construct a rich understanding of the addition and subtraction operations.

The problems presented should be structured like Cognitively Guided Instruction (CGI) if you are familiar with that. In short, instead of “adding” and “subtracting,” you “join,” “separate,” use “part-part-whole,” and “compare.” Any of the quantities you work with (initial/starting amount, change amount, resulting amount) can be the unknown. For example, here is a part-part-whole problem with the initial amount unknown:

Jayden had some jelly beans. She ate 13 of them on Monday morning. One Monday afternoon she ate the remaining 12. How many jelly beans did Jayden begin with?

Contextual problems must be somehow connected to the children’s lives. You could write your own problems easily by reading some samples presented in the book. Problems could be about a recent experience the class had together such as a field trip, a discussion in another content area, or your read-aloud (or another book you’ve all read).

A typical development for students to make in early math is as follows:

  1. Uses counters and counts everything seen
  2. Counts on from the first set given
  3. Counts on from the largest set
  4. Uses facts retrieved from memory and relies less on counters

Part of what will help children progress to the next stage of mathematical development is to teach with models, showing what to do every step of the way, being sure to use a variety of kinds [Designs, picture "stories," unifix cubes, 2-colored counters (or other object), or part-part-whole mat] in order to give students different ways to see the problem and to model how to use each kind of model.

When teaching these first two operations, teach addition and subtraction simultaneously. If you ask what 7 – 3 is, you must also ask what 5+3 is  so students will learn the pattern. Subtraction must be taught as “Think-Addition,” instead of “Count What’s Left.” So instead of subtracting 6 counters from a student’s pile of 9 counters and asking them for the answer by counting what remains or asking what is 9 – 6 , help your students ask the question 6 and what make nine? As kids practice with each other in pairs, they say and write the equations that match with their problems. This is actually the beginnings of algebra.

Lastly, something we often don’t think of because it seems so obvious to us as adults. When teaching addition and subtraction, help children understand the “Order Property” (usually known as the commutative property) and the “Zero Property.” Using understanding of the order property, you learn that when adding two numbers together, the order of the addends don’t affect the result. Using the zero property, you learn that any number plus or minus zero is that number. Van de Walle here says that some students really do get confused because they connect the idea of addition with a number getting larger and subtraction with a number getting smaller, so to some, 12 – 0 should be less than 12, so some students may write an answer of 11.

Teacher Resource
http://www.aaamath.com/
This is a nice little site that offers tutorials and definitions of 25 different math topics for K-8 grades. You can sort by grade or subject. After each tutorial there is an interactive practice application that produces problems and automatically checks answers. I advise you to check out the practice prior to assigning it to a student because I tried the fraction subtraction practice (that’s a mouthful!) and it wouldn’t accept reduced answers. For example, it wanted the answer 2/2 and not “1.” This is reasonable, just something the student should know.

NEXT: PART 2: MULTIPLICATION & DIVISION

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