Grade 7 Proportions: Unit Review

Worked examples

Real problems from the practice worksheets, solved one step at a time.

1. Example 1

   Solve: 7/42 = x/84

   1. Compare the known denominators: 42 × 2 = 84, so the fraction was scaled up by 2.
   2. Scale the numerator by the same number: 7 × 2 = 14.
   3. Check: 7/42 = 14/84. So x = 14.

   Answer: 14

2. Example 2

   Solve: 37/36 = x/180

   1. Compare the known denominators: 36 × 5 = 180, so the fraction was scaled up by 5.
   2. Scale the numerator by the same number: 37 × 5 = 185.
   3. Check: 37/36 = 185/180. So x = 185.

   Answer: 185

3. Example 3

   Solve: 18/31 = x/124

   1. Compare the known denominators: 31 × 4 = 124, so the fraction was scaled up by 4.
   2. Scale the numerator by the same number: 18 × 4 = 72.
   3. Check: 18/31 = 72/124. So x = 72.

   Answer: 72