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7th grade · Math · Unit 9 of 17

Percents & Proportions

Increase, decrease and proportional

What your child practices

Knowing common fraction, decimal and percent equivalents, increasing and decreasing numbers by 1%, 5%, 10%, 25%, 50% and 100%, and deciding whether a relationship is proportional.

Alaska content standards learning standard: 7.RP.2; 7.RP.3 · proportional relationships and percent increase and decrease

How we explain it

Children can open this short lesson before they practice.

  1. Know common matches: 1/2 = 0.5 = 50%, 1/4 = 0.25 = 25%.
  2. To increase by a percent, multiply by 1 plus the percent as a decimal.
  3. A proportion says two ratios are equal.

Example: Increase 80 by 25%. 25% of 80 = 20. 80 + 20 = 100. Answer: 100

Percents & Proportions in Alaska

In the Alaska content standards, this is unit 9 of 17 in 7th grade Math, after Fractions and before Algebra Moves.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Alaska Department of Education and Early Development

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    4 notebooks cost $9.68. At the same price, how much do 8 notebooks cost, in dollars?

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  2. Question 2

    Decrease 194 by 50%. What is the new number?

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  3. Question 3

    Which decimal is equal to 5/8?

    • 0.25
    • 0.2
    • 0.625

  4. Question 4

    A person is 150 cm tall at age 10 and 160 cm tall at age 11. Is height proportional to age?

    • Yes, because both go up
    • Yes, because it grew 10 cm
    • No, height does not double when age doubles

  5. Question 5

    Decrease 100 by 25%. What is the new number?

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  6. Question 6

    Increase 256 by 100%. What is the new number?

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