Solving ProportionsTwo equal ratios, and the cross-multiplication that solves…7th GradeIf two ratios are equal, the cross productsare equal. That turns a proportion into aone-step equation.a/b = c/d → ad = bc3/4 = x/20x = 153 × 20 = 4x, so 60 = 4x.x/5 = 12/15x = 415x = 60.2 kg costs £3, 7 kg?£10.503/2 = x/7 → 2x = 21.Scale 1 : 50, model 6 cm300 cm realScale factors are just proportions.THE COMMON MISTAKE✗ 3/4 = x/20 → x = 3 × 4 × 20✓ 3/4 = x/20 → 4x = 60 → x = 15Cross multiply gives an equation to solve, not the answer itself.Label both fractions with units. If the units are not in matchingpositions, the setup is wrong.Solving Proportionswww.littleactivity.com

Full preview — nothing is watermarked or held back.

Math · 7th Grade

Solving Proportions

Two equal ratios, and the cross-multiplication that solves them.

How to use it

Set it up with the same quantity on top of both fractions. Units keep you honest.

Free · print-ready PDF · US Letter and A4

Grade
7th Grade
Ages
12–13
Subject
Math
Pages
1

The rest of the 7th Grade wall

49 more posters, all free to print — 11 of them here.

Your Cart (0)

Your cart is empty

Browse our shop to find activities your kids will love