cover

Math's Running Shoes

What is multiplication really, and how is it just fast adding?
~~Here's a small secret~~ hiding inside every math class: **multiplication isn't some new, scarier kind of math**. It's

Here's a small secret hiding inside every math class: multiplication isn't some new, scarier kind of math. It's just addition wearing a fast pair of running shoes. That's the whole trick. Let's go catch it in the act.

~~Imagine you're setting tables for a party.~~ Each table needs 4 plates. You set one table, then another, then another

Imagine you're setting tables for a party. Each table needs 4 plates. You set one table, then another, then another โ€” four plates, four plates, four plates. You're adding the same number over and over. That repeating sameness is the soil where multiplication grows.

Now suppose there are five tables. You could whisper "4 plus 4 plus 4 plus 4 plus 4" and count it up โ€” and you'd get the

Now suppose there are five tables. You could whisper "4 plus 4 plus 4 plus 4 plus 4" and count it up โ€” and you'd get the right answer, 20. But saying that out loud is a mouthful. Math, like most of us, prefers a shortcut.

So we shrink that whole sentence down to **two little numbers** and an "ร—". We write "++5 ร— 4++." It means exactly the s

So we shrink that whole sentence down to two little numbers and an "ร—". We write "5 ร— 4." It means exactly the same thing: "the number 4, added together 5 times." The ร— is really just a sign that says, "do that repeated adding for me, quickly."

This is why people call multiplication "~~fast adding~~." **It's not magic** and it's not different math โ€” it's the same

This is why people call multiplication "fast adding." It's not magic and it's not different math โ€” it's the same pile of plates, just bundled up into a neat package so you don't have to count every single one by hand.

~~Here's the lovely part.~~ It works **no matter which way you turn it**. "5 ร— 4" gives 20, and so does "4 ร— 5." *Five g

Here's the lovely part. It works no matter which way you turn it. "5 ร— 4" gives 20, and so does "4 ร— 5." Five groups of four, or four groups of five โ€” same total. Think of a chocolate bar: rows times columns gives the squares, whichever side you start counting from.

And this is where multiplication earns its running shoes. Picture a huge stadium with 30 rows and 50 seats in each row.

And this is where multiplication earns its running shoes. Picture a huge stadium with 30 rows and 50 seats in each row. Adding "50 plus 50 plus 50..." thirty times would take ages. But "30 ร— 50" hands you 1,500 in one quick swoop. The bigger the job, the more time multiplication saves.

~~So the next time someone says, "multiply,"~~ _don't picture something brand new_. Picture **a long line of identical g

So the next time someone says, "multiply," don't picture something brand new. Picture a long line of identical groups, and a tiny "ร—" rolling up its sleeves to add them all at once โ€” so fast you barely see it happen.

That's the whole secret. Multiplication is just **addition in a hurry** โ€” the same friendly idea, simply ~~too quick to

That's the whole secret. Multiplication is just addition in a hurry โ€” the same friendly idea, simply too quick to walk. Every time you skip-count, you're already doing it. You've known this magic trick all along.

How was this book?

A Wonderleaf Book

Math's Running Shoes

โ€” What is multiplication really, and how is it just fast adding? โ€”

Wonderleaf Editions
โ€” ex libris โ€”
A Wonderleaf Book

Math's Running Shoes

What is multiplication really, and how is it just fast adding?

Wonderleaf Editions ยท MMXXVI
Scene 1
~~Here's a small secret~~ hiding inside every math class: **multiplication isn't some new, scarier kind of math**. It's
Math's Running Shoes2
Scene 1

Here's a small secret hiding inside every math class: multiplication isn't some new, scarier kind of math. It's just addition wearing a fast pair of running shoes. That's the whole trick. Let's go catch it in the act.

3Math's Running Shoes
Scene 2
~~Imagine you're setting tables for a party.~~ Each table needs 4 plates. You set one table, then another, then another
Math's Running Shoes4
Scene 2

Imagine you're setting tables for a party. Each table needs 4 plates. You set one table, then another, then another โ€” four plates, four plates, four plates. You're adding the same number over and over. That repeating sameness is the soil where multiplication grows.

5Math's Running Shoes
Scene 3
Now suppose there are five tables. You could whisper "4 plus 4 plus 4 plus 4 plus 4" and count it up โ€” and you'd get the
Math's Running Shoes6
Scene 3

Now suppose there are five tables. You could whisper "4 plus 4 plus 4 plus 4 plus 4" and count it up โ€” and you'd get the right answer, 20. But saying that out loud is a mouthful. Math, like most of us, prefers a shortcut.

7Math's Running Shoes
Scene 4
So we shrink that whole sentence down to **two little numbers** and an "ร—". We write "++5 ร— 4++." It means exactly the s
Math's Running Shoes8
Scene 4

So we shrink that whole sentence down to two little numbers and an "ร—". We write "5 ร— 4." It means exactly the same thing: "the number 4, added together 5 times." The ร— is really just a sign that says, "do that repeated adding for me, quickly."

9Math's Running Shoes
Scene 5
This is why people call multiplication "~~fast adding~~." **It's not magic** and it's not different math โ€” it's the same
Math's Running Shoes10
Scene 5

This is why people call multiplication "fast adding." It's not magic and it's not different math โ€” it's the same pile of plates, just bundled up into a neat package so you don't have to count every single one by hand.

11Math's Running Shoes
Scene 6
~~Here's the lovely part.~~ It works **no matter which way you turn it**. "5 ร— 4" gives 20, and so does "4 ร— 5." *Five g
Math's Running Shoes12
Scene 6

Here's the lovely part. It works no matter which way you turn it. "5 ร— 4" gives 20, and so does "4 ร— 5." Five groups of four, or four groups of five โ€” same total. Think of a chocolate bar: rows times columns gives the squares, whichever side you start counting from.

13Math's Running Shoes
Scene 7
And this is where multiplication earns its running shoes. Picture a huge stadium with 30 rows and 50 seats in each row.
Math's Running Shoes14
Scene 7

And this is where multiplication earns its running shoes. Picture a huge stadium with 30 rows and 50 seats in each row. Adding "50 plus 50 plus 50..." thirty times would take ages. But "30 ร— 50" hands you 1,500 in one quick swoop. The bigger the job, the more time multiplication saves.

15Math's Running Shoes
Scene 8
~~So the next time someone says, "multiply,"~~ _don't picture something brand new_. Picture **a long line of identical g
Math's Running Shoes16
Scene 8

So the next time someone says, "multiply," don't picture something brand new. Picture a long line of identical groups, and a tiny "ร—" rolling up its sleeves to add them all at once โ€” so fast you barely see it happen.

17Math's Running Shoes
Scene 9
That's the whole secret. Multiplication is just **addition in a hurry** โ€” the same friendly idea, simply ~~too quick to
Math's Running Shoes18
Scene 9

That's the whole secret. Multiplication is just addition in a hurry โ€” the same friendly idea, simply too quick to walk. Every time you skip-count, you're already doing it. You've known this magic trick all along.

19Math's Running Shoes

~ finis ~

Tiny picture books for big little questions.

โ€” a small constellation of questions โ€”
โœฆWonderleaf
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