Proportion Definition: a plain-English explanation of what the term means, why it matters in math, and how it is used, followed by worked examples and practice questions so the definition turns into something you can apply.
A proportion states that two ratios are equal, like 3 over 4 equals 6 over 8. Solving one means finding the missing value, usually by cross multiplication.
Math Dictionary / Proportion
Proportion
A proportion is an equation that says two ratios are equal.
Ratios and ProportionsGrade 6Grade 7Grade 8Algebra 1GEDSATACT
What it means
Proportions are often used to solve scale, percent, and rate problems.
Also called: equal ratios
Examples
| 1/2 = 3/6 |
| If 4 apples cost $6, 8 apples cost $12 |
| Scale drawings use proportions |
Common mistake
Both ratios must compare quantities in the same order.
Try one
Question: Are 2/5 and 6/15 proportional?
Show answer
Yes. 2/5 = 6/15.