How_To_Be_Good_At_Math

NUMBERS • PLACE VALUE 13

÷10 ÷10 ÷10 ÷

When we divide by 10,

digits move one place

value to the right

When we

multiply by

10, digits

move one

place value

to the left

×10 ×10 ×10 ×

Th H T O

4 3 7

4 3 7 0

4 3 7

Ten times bigger or smaller

Each column in the place-value system increases or decreases

the value of a digit by 10. This is really useful when we multiply

or divide a number by 10, 100, and so on.

Let’s look at what happens to 437

when we multiply or divide it by 10.

If we divide 437 by 10, each digit

moves one column to the right.

The new number is 43.7. A dot, called

a decimal point, separates ones from

numbers 10 times smaller, called tenths.

2000

500

70

• 6

2576

5 hundreds

7 tens

When we write this again with

numbers, using zeros as

place holders, we get four

separate numbers.

When we put the digits into

columns, we can see how

many thousands, hundreds,

tens, and ones the number is

made of.

To multiply 437 by 10, we move

each digit one column to the left.

The new number is 4370, which is

437 × 10.

6 ones

Now, if we add up the four

numbers, we get 2576, our

original number. So, our place

value system works!

Th H T O

2 5 7 6

Th H T O

2 5 7 6

2 0 0 0

7 0

6

The value of 2

in this number

is 2000 because

of its position

2 thousands

How place value works

Let’s look at the number 2576 and think some

more about how place value works.

5 0 0

.

Decimal point

001

Tenths

012_013_Place_Values.indd 13 29/02/2016 14: