Fractions, Decimals, Percents

October, 2013

Reminder… Numerator represents the…

“part”

Denominator represents the…

“whole”

So,

Example: There were 15 elephants in the zoo that has 236 animals. Write a fraction representing this situation.

wholepart

Types of Decimals Examine the decimal below. What do you

notice?

6.375

Terminating Decimal: Any decimal that “terminates”

“Terminates” means “to end or stop”

Examples of Terminating Decimals:

5.67 4.23

-6.901 -3.75

A terminating decimal is part of the real number system. How is it classified?

Examine the decimals below. What do you notice?

6.33333….

Repeating Decimal: Any decimal that has a constant pattern of digits that repeat.

Examples:

5.3333… “3” is the repeating digit

6.3030… “30” is the repeating pattern

-1.233233… “233” is the repeating pattern

3.6

Repeating Decimals

A repeating decimal is part of the real number system. How is it classified?

Bar Notation:

The line above the repeating digits

only occurs over the repeating part

Examples:

1.34 1.23 16.598

Fractions, Decimals & Percents

All three have the same value, they are just represented in different ways.

CAN calculate with fractions AND decimals!

CANNOT calculate with percents!

Note to self:

Use “Examples” document for practice on each section.

FRACTIONS TO DECIMALS

Fractions to Decimals

Any fraction can be written as a decimal –

How?

Divide the numerator by the denominator.

YOU MUST BE ABLE TO SHOW THIS USING LONG DIVISION!!

5/8 = .625

2/5 = .40

FRACTIONS TO PERCENTS

Fractions to Percents

Percent means…“Per 100” or “Out of 100”

Fractions to Percents

Make the fraction a decimal and multiply by 100 (move decimal 2 places to right)

1/4 = .25 = 25%12/25 = .48 = 48%

You try! Fraction to Decimal: (use long

division)

Fraction to Percent:

53

97

1

87

506

DECIMALS TO FRACTIONS

Decimals to Fractions

“SAY” the decimal and create the fraction …then, simplify!

.35 = 35/100 = 7/20.217 = 217/1000

Repeating Decimals to Fractions

How do you make a repeating decimal into a fraction?There is a very complicated process that ultimately says “take the repeating part of the decimal and put it over a denominator that has the same number of 9’s.”

Example – 0.3333… = 3/9 = 1/3

.484848… = 48/99

DECIMALS TO PERCENTS

Decimals to Percents

Multiply by 100 (move decimal 2 places to right)

.25 = 25%.48 = 48%

Decimals to Percents

D ----- P

D ------- P

You Try!

Decimals to Fractions:0.52 0.8

Decimals to Percents:0.13 0.192

PERCENTS TO FRACTIONS

Percents to Fractions

Percent = “Per 100” or “Out of 100”…Removing the % sign and

placing the number over 100.

23% = 23/100

55% = 55/100 (simplify)

PERCENTS TO DECIMALS

Percents to Decimals

Divide the percent by 100 (move decimal 2 places to the left)

23% = .23

64% = .64

Percents to Decimals

D ----- P

D ------- P

You Try!

Percents to Fractions:85% 1%

Percents to Decimals:21% 27.3%

Quick Tip – Decimal/Percent

.83

46%

FormativeClean Sheet – Practice – 1 of 3

Write each fraction as a decimal (use long division).1/8 5/9 7 ½

Write each decimal as a fraction..22 0.1 4.6

Practice – 2 of 3

Write each fraction as a percent.¼ 6/10 17/20

Write each percent as a fraction.90% 75% 22%

Practice – 3 of 3

Write each percent as a decimal.27% 70% 6%

Write each decimal as a percent..95 .08 5.8