How Food Examples Illuminate Tough Math Concepts

 I have been teaching math concepts for a long time.

First as a 2nd grade teacher, then a 4th grade teacher, and then as a mom.

Now I am back in classrooms again as an instructional assistant, and a lot of my job involves helping the kids who need extra help understanding the math concepts.

In every case, I have found that over and over again, food related mental pictures are what takes the student from being in the dark to the light going on in their eyes, and that brilliant moment where they can say with pride, “I get it now!”

I want to help every child’s light go on, even at schools that I am not a part of, and so I decided to share a few of these examples. I will take no offense if you already have perfect examples for all these concepts, but in the hopes that if there is a teacher out there, searching for just the right example to help “that student,” here are the mental food pictures I find to be the most helpful.

Cookies and “Mean Mom” to teach basic addition and subtraction

When I was starting to teach my kids about addition, I started with various versions of a simple concept. I would say imagine you have three cookies (or something else sweet), and I gave you one more, how many would you have?

Being kids with a sweet tooth, it was easy enough for them to imagine getting more of their favorite treat. I started simple, just going up by one, but as they got the concept, I could change the numbers and increase the difficulty.

Subtraction is a harder concept for many kids. For some reason, I find that when you say “take away” so many from the total, it is not intuitive to their young mind what exactly is happening.

So, I “eat” when we practice subtraction. In our car rides, my kids would get to say how many cookies (candy, brownies etc) they had on their imaginary plate. Then “mean mom” would sneak in and eat a certain number of them! I always said it very dramatically, and frequently got them to laugh at the mental picture of stealing and eating their sugary treats. But they understood.

When you take something away, there is still somewhat of a lingering concept of wondering if it is still around. But eating, that’s clear, and definite, and the food isn’t coming back.

My kids also liked to reverse it, where they were the “mean” one, who sneakily stole my food instead. But in both cases, they were the ones subtracting, and solving the problem.

I used this again last week at school, where one student was confused on the idea of subtraction, and I told her to imagine she had so many chocolates, and I sneakily ate some of them. She laughed at me, and even told her teacher how funny I was, but she also understood it. By the end of our little time together, she was accurately subtracting more often than not.

Multiplication and the cookie boxes

The crucial idea for multiplication is understanding “groups of” when they see the multiplication sign.

Typical word problems deal with desks in rows, or distributing stickers, etc. But my default is to cookie boxes.

A typical mental picture for 5x6 might be: Imagine you have five boxes of cookies, and each box has six cookies in it, how many cookies would you have?

In my experience, kids like the idea that each group is contained within the box, but you can count the items inside, and the idea that the more boxes you have the more you have that amount of cookies seems to resonate with them. It is also very easy to illustrate on paper by drawing rectangles with various amounts of circles with them.

Multiplying by one makes more sense. If you have one box, with however many cookies you put inside, it is easy to see that is the amount of cookies you have. You won’t be tempted to add one, because why would you add a box to your amount of cookies?

Multiplying with zero also makes more sense. A box with zero cookies in it is very sad. And it clearly means you have no cookies. It doesn’t matter how many empty boxes you have, you still have no cookies. The reverse is also true. It doesn’t matter how many cookies come in a box, if you have no boxes. You still have no cookies.

Dividing with Skittles (or M&Ms)

Division is a very hard concept for many kids. They are asked to do something vastly different from the addition or subtraction that they learned when they were younger. Multiplication as repeated addition is comparatively easy.

But division isn’t just repeated subtraction because it is about being fair.

The biggest take home we want for our kids with division problems is to know that you are taking the total amount, and distributing it the specified number of times so that all groups get an equal portion.

Confusing.

What makes sense to the kids is sharing a treat. Like Skittles or M&Ms. These treats come in a package with an unknown amount. They can easily imagine that they might have friends to eat these with.

So, say I was introducing the problem six divided by three. Many kids will tend towards the answer of 3. Why? Because they learned that 3+3=6, and that fact is entrenched in their brain.

At this point, I will say imagine that there are 6 Skittles, and three friends want to eat them. How many can each person have? If they still try out the number three, I pretend to start passing them out. Ok, the first person gets three, the next person gets three… and oh no, the last person doesn’t get any!

Most of the time, just to drive home the idea of fairness, I will have the person who gets zero be the child doing the problem. They definitely don’t want to divide in a way that keeps them from having a treat. So they try again, until I can give each friend the same amount.

The more I use Skittles with a group learning division, the more they catch on, and I even hear them going through to themselves, “if I have ___ and this many people want to eat them ___, then we each get ____.” This is a great moment as a teacher, because it shows they understand what the numbers on the page are truly asking.

Again, the concept of dividing by one makes more sense. However many Skittles you have, if you only have to share them with yourself- then you get to eat that many.

Continue reading on Medium:

https://medium.com/age-of-awareness/how-food-examples-illuminate-tough-math-concepts-2cdeb475f7fe