Fractions to Decimals



Chapter 5: Fractions, Decimals, and Percents Study Guide

Fractions to Decimals

• When you have a fraction that can be written as a “friendly fraction” (a fraction that has a power of ten in the denominator), you can use the numerator as the digits for the decimal.

5 37 = 5.37 9/10 =__________ 10/25 = 40/100 = .4 2/5 = ____________

100

• When you have fractions that cannot be written as “friendly factions” you must divide the numerator by the denominator. So….you must do long division!

• Remember: The three steps to get set up are:

1. Write a decimal next to the numerator

2. Bring up your decimal

3. Write in your place holder 0

5/16 = 5/12 =

Remainder

Decimals to Fractions

• To write a terminating decimal as a fraction, the digits of decimal are the numerator, and the denominator is the place value of the last digit.

• REMEMBER TO WRITE THE FRACTION IN SIMPLEST FORM.

.567 = 567/1000 3.67 = 3 67 .25 = ___________ .9 = ___________

100

Decimals to Percents

• D2P: Move your decimal place to the right two places.

• This is because you are really MULTIPLYING BY 100.

.56 = 56% 2.39 = 239% .45 = ___________ 1.05 = __________

Percents to Decimal

• P2D: move your decimal to the left two places

• You are really DIVIDING BY 100.

67% = .67 103% = 1.03 89% = _________ 50% = ___________

Fractions to Percents

• If a fraction can be written with a denominator of 100, then the numerator is the percent.

• If the fraction cannot be written with a denominator of 100, then you must convert it to a decimal by long division and then a percent.

4/25 = 16/100 = 16% 15/20 = __________ = _____________

Percents to Fractions

• The given percent is the numerator and the denominator is 100. (Percents are always compared to 100.)

• You must put the fraction in lowest terms.

59% = 59/100 72% = 72/100 = 18/25 18% = _______________

COMPARING DECIMALS, PERCENTS & FRACTIONS

Just Decimals

• You must know about PLACE VALUE because you will be asked to read decimals in “math language”

• You must be able to order decimals: DRAW YOUR COLUMNS to compare each place value one at a time

Order from least to greatest: .285, .28, 6.27, 6.29, 6.08

Line up your decimal so you can compare your place value:

.285

.28 .28, .285, 6.08, 6.27, 6.29

6.27

6.29

6.08

Order from greatest to least: 7.56, 7.5, 7.056, 7.34

Just Fractions

• Always use the BENCHMARK strategy first. (Compare to 0, ½, and 1)

• If that doesn’t help, draw a picture, convert to decimals or use the LCD

6 8 9 12 55 14

9 11 10 13 100 20

Comparing All Three At Once!!!!!

Either:

• Make them all a percent

• Make them all a decimal

• Make them all a fraction

• USING BENCHMARKS HERE CAN BE HELPFUL

Order from least to greatest:

4/5, 55%, .45 2/6, .25, 30%

Show work: Show work:

4/5 = .60

55% = .55

.45 = .45

.45, 55%, 4/5

IMPORTANT NOTES:

• It would be extremely helpful to know all the fractions on your blue reference sheet.

• You will also be asked to write fractions and percents represented by pictures.

• For extra practice you can play any fraction, decimal, and percent game on the internet. Here are a few:

Comparing Fractions, Decimals, and Percents:

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• Comparing Fractions:

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