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Fractions, Decimals, and Percents

Mr. Swaner

A Quick Review

- Fractions, decimals, and percents are all parts

of a whole. They are also related and can be

converted back and forth.

1

0

.25 25

.50 50

0 0

.75 75

1

100

Decimals

- Decimals are like fractions because they also

represent parts of a whole, however, decimals use

the base ten system by place value. The place is

named by the furthest right number.

tenths, hundredths, thousandths, ten thousandths,

hundred thousandths.

0.1 is said one tenth because the furthest

right number is in the tenth place.

0.17 is said seventeen hundredths for the same

reason,

How would we say 0.83

Eighty-three hundredths

How would we say 0.015?

fifteen thousandths,

Converting decimals to fractions

- Converting decimals to fractions is easy because

all we have to do is read the decimal and it

sounds the same as when we read the fraction. - We read 0.3 as three tenths. which is
- 0.41 is read forty-one hundredths.

- .07
- .13
- .3
- .107

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Fractions in base 10

- Fractions in base 10 (denominator 10, 100,

1000..) are easy because they are also read the

same way as decimals

Say it and Write it

Converting Fractions to Decimals

- If the fraction has a denominator in base ten

(10, 100, 1,000 etc.) It works the same way. - is 0.07 both are read seven hundredths.
- If the fraction does not have a base ten

denominator, you must use long division until you

get a repeating or terminating decimal.

Dividing out a Fraction

When dividing the fraction, it is important to

make sure you have the right number in the

house, or inside the division symbol

house

house

basement

Dividing out a Fraction

When dividing the fraction, it is important to

make sure you have the right number in the

house. or inside the division symbol

house

house

basement

Lets Try a Few

- Convert 0.49 to a fraction
- Convert .083 to a fraction
- Convert to a decimal
- Convert to a decimal
- Convert to a decimal

Lets Try a Few

- Convert 0.49 to a fraction
- Convert .083 to a fraction
- Convert to a decimal
- Convert to a decimal

- I wish I could do this sometimes during the

summer!

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These are called terminating decimals

- A terminating decimal ends

A Repeating Decimal

- Ummmmmm it repeats. Use a bar to show it repeats

Day 2?

Warm Up

- 1) convert 0.16 to a fraction
- 2) convert to a decimal
- 3) convert to a decimal

Converting Numbers into Percents

- When you have a fraction with a denominator in

base 10 (10, 100, 1,000), numbers can be easily

converted into percents. - The word percent literally means per hundred.
- means you have 40 per hundred or 40
- How could we easily find what percent is?

Converting Decimals to Percents

- Lucky for us, decimals are ALL in base ten.
- 0.72 means 72 per hundred or 72.
- What happens if we have 0.851
- How many hundredths are there?
- The left over is just a decimal
- An easy rule for converting decimals to percents

is to simply move the decimal 2 places right.

85

85.1

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Lets Try Some

Percents to Decimals and Fractions

- To convert a percent to a decimal, we do the

reverse. Instead of moving the decimal 2 places

right, we move it 2 places left and drop the

sign.

Try One on Your Own

Convert 27 into a decimal

Now convert 0.27 into a fraction

Closure

- How do you convert a decimal to a fraction?
- How do you convert a fraction to a decimal?
- How do you convert a decimal to a percent?
- How do you convert a percent to a decimal?

Write it as it is read

Long divide

Move the decimal right 2 places

Move the decimal left 2 places