Subscribe

7th grade · Math · Unit 8 of 20

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.

New York State Learning Standards learning standard: NY-7.RP.2; NY-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 New York

In the New York State Learning Standards, this is unit 8 of 20 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: New York State Education Department (NYSED)

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 $8.60. At the same price, how much do 6 notebooks cost, in dollars?

    answer box

  2. Question 2

    Which percent is equal to 3/4?

    • 37.5%
    • 75%
    • 20%

  3. Question 3

    Which decimal is equal to 5/8?

    • 0.375
    • 0.2
    • 0.625

  4. Question 4

    What number makes these ratios equal?

    2 : 4 = 12 :

    answer box

  5. Question 5

    Decrease 190 by 50%. What is the new number?

    answer box

  6. Question 6

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

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

More 7th grade