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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.

Maine Learning Results learning standard: 7.RP.A.2; 7.RP.A.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 Maine

In the Maine Learning Results, 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: Maine Department of Education

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

    Decrease 900 by 1%. What is the new number?

    answer box

  2. Question 2

    Increase 140 by 10%. What is the new number?

    answer box

  3. Question 3

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

  4. Question 4

    Which decimal is equal to 3/8?

    • 0.7
    • 0.15
    • 0.375

  5. Question 5

    Which percent is equal to 3/8?

    • 70%
    • 62.5%
    • 37.5%

  6. Question 6

    Increase 280 by 5%. What is the new number?

    answer box

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