Chapter 2 Review Sheet Test Date: ______

Fractions, Decimals, & Percents

How to prepare for a math test

  • Read through this review sheet to determine what you know and what you don’t know. Focus your study time on what you don’t know first.
  • Review vocabulary, reference sheets, notes, and key concepts
  • Try problems from the practice packet in your binder. Remember, answers are on the back!
  • Go to

Log in and use any of these resources:

Watch – a purple button that is a personal tutor for each concept

Check – the red check mark that is a quick quiz on a concept

Response to Intervention – RtI button has very basic explanations of

concepts with additional practice pages

Worksheets – a green button that has extra worksheets for concepts you

may want to practice more

  • Ask for help! See Mrs. Blue during team support; ask a friend or a parent.
  • Get a good night’s sleep and eat a good breakfast!

Key Concepts

Decimals & Fractions

  • Write decimals as fractions or mixed numbers

Hint: say the decimal properly & you will hear the fraction!

  • Write fractions mixed numbers as decimals
  • Scale up to a denominator of 10, 100, 1000 etc. then say the fraction & you’ll hear the decimal.
  • Use long division: numerator denominator

Percents & Fractions

  • Percent means “part per 100”
  • Write a percent as a fraction: Ex: 5% =
  • Write a fraction as a percent
  • Make an equivalent fraction out of 100
  • If the denominator can’t be scaled up easily to 100, then scale down to a factor of 100, then scale back up to 100

Percents & Decimals

  • Write percents as decimals
  • Write the percent as a fraction out of 100, say the fraction, write the decimal
  • Divide the percent by 100 ~ this moves the decimal point left two places
  • Write decimals as percents
  • The numbers in the first two places are the % Ex: 0.38 = 38%
  • Don’t lop off the extra digits. Ex: 0.3875 = 38.75%
  • Say the decimal, write it as a fraction, find an equivalent fraction out of 100, the numerator is the %
  • Multiply the decimal by 100 ~ this moves the decimal point to the right 2 places

Percents > 100% & <1%

  • 100% = 1.0
  • 0.2% 20%

0.2% is %, this is less than 1%, be careful how you write it!

0.2% = 0.002

  • To convert mixed numbers or decimals >1.0 to a percent, split the problem apart. Find the % for the whole number and the percent for the fraction/decimal and add them.

Ex: 2 2 = 200% = 20% so 200% + 20% = 220%

Ordering Fractions, Decimals, Percents

  • Compare the numbers in the same form.
  • Equivalent fractions
  • Percents
  • Look at place value in decimals

10% Thinking

  • Find 10% of a number by dividing by 10

Ex: 10% of 240 = 24

  • Then use the value of 10% to find any other percent of a number by scaling up or down

Ex:10% = 24

20% = 48 (doubled 10%)

5% = 12 (split 10% in ½)

Estimate the % of a number

  • Use compatible numbers – numbers that work together easily
  • Should be easy mental math problems
  • Strategies:
  • 10% Thinking
  • Fractions
  • Equivalent ratios
  • Rate out of 100

Find the percent of a number

  • Use 10% thinking
  • Multiply the percent (as a fraction) by the number
  • Multiply the percent (as a decimal) by the number
  • Determine the price of an item that is on sale

Proportions

  • What is a proportion?
  • In a percent proportion one ratio compares and the other ratio represents the percent as
  • How can proportions help you solve for unknown quantities?
  • Solve percent proportions.

Ex: 75 is 15% of what #?