Playing With Math

Do you enjoy math? Some kids think it’s

? scary, but it really can be fun. Math becomes easier when you learn to break down problems into smaller pieces.

Keep it simple

You don’t have to keep big numbers in your head. The main trick is to break down big numbers into simpler ones. When you do that, hard problems become easier.

For example, when you read, you probably break things down into simple parts without

even thinking about it. When you = sound out a word, for example, you

4 are breaking it into

different parts.

People who can solve one kind of problem are probably good at solving other kinds of problems. They’ve learned how to break things down into simple pieces. They can also see patterns and how things fit together.

Use rhymes to remember

If you want to multiply by 5, how would you do it? What is 5 x 66?

An easy thing to do is to multiply 66 by 10 and then cut it in half. (Five is half of 10.) Half

of 660 is 330.

6

In the book “The Grapes of Math,” author Greg Tang uses

poems as an aid:

“A group of 5 you’ll find with ease. “Half of 10 is just a breeze.”

Now try multiplying by 9. Can you multiply 9 x 6? How about 9 x 89? Remember to break the problems into simpler parts. Here’s Greg’s poem to help you:

“A group of 9 requires tact.

“Start with 10 and then subtract.” (10 - 1 = 9)

Try it! We’ll give you the answers first:

9 x 6 = 54 9 x 89 = 801

So ... So ...

10 x 6 = 60 10 x 89 = 890

60 - 6 = 54 890 - 89 = 801

Number tricks

Once you understand how numbers work, you can play all sorts of games with them.

For example, you can learn to multiply two-digit numbers by 11. Let’s start with:

What is the same about the middle number in each answer?

72 81 44 x 11 x 11 x 11

792 891 484 In all these answers, we added together the two digits in the original number. (7 + 2 = 9, 8 + 1 = 9, 4 + 4 =8) The sum is now in the middle of the multiplication answer.

You can also remember that when you are multiplying by 11, you are really multiplying by 10, then multiplying by 1. Then you add the answers together.

45 45 45 x 10 x 1 x 11

450 45 495

Mini Fact: “Eleven plus two” and “Twelve plus one” are anagrams of each other, and both are equal to 13!