Decimals

The relationship between fractions and decimals

2

What fraction of the rectangle is green?

What decimal part of the rectangle is green?

10

6

.6

They sound alike!!!

To write a decimal as a fraction, write the fraction as you would

say the decimal

0.12345

tenths

Hundredths

Thousandths

Ten-thousandths

Hundred-thousandths

Say the decimal….Write it as a fraction

• .5

• .65

• .22

• .2

• .225

Notice….when you change a decimal to a fraction the denominator is always 10, 100, 1000 (powers of ten!)

Is that all there is?

You have to simplify the fraction if possible

Write .6 as a fraction

.6 = 10

610

6 Can be simplified to:

5

35

3.6 =

What about fractions to decimals?

You can write a fraction as a decimal by dividing the numerator by the denominator…..the fraction symbol means division!

344

3 To make a

decimal…do the division!

34 .0028

20200

.75

One more thing………

When you divide, REMEMBER, add zeros to finish your division.

2 THINGS CAN HAPPEN

4.255

2

The division problem ends

A Terminating decimal

.......333333333333333.266

2

The division problem goes on forever….Repeating decimal

Repeating Decimals

A single digit might repeat….

.3333….

Or a group of digits might repeat…

.275275275….

Show repeating decimals by placing a line over the digit or

group of digits that repeats

.33333…. Becomes .3

And

.275275….becomes .275

Remember

5

21 Will be 1.4

1.2 will be 10

21 Simplified to:

5

11

Whole numbers stay the same!

Homework

Page 212 in your textbook….

Problems 14-38

Start now!