Definition
Ratio table
A ratio table lines up pairs of quantities that keep the same multiplicative relationship.
| Stars | Beads |
|---|---|
| 1 | 3 |
| 2 | 6 |
| 4 | 12 |
| 5 | 15 |
What it means
Read each pair together. If one quantity is doubled, tripled, or divided, the other must be changed by the same factor. That is what keeps every pair equivalent. The headings matter: they tell you which quantity each row or column contains.
Remember it
Two quantities travel together: whatever scale factor one gets, the other gets too.
Example
A craft uses 3 beads for every 1 star. A ratio table can show 1 star with 3 beads, 2 with 6, 4 with 12, and 5 with 15. To find the beads for 7 stars, multiply both parts of 1:3 by 7, giving 7 stars and 21 beads.
Watch for
A two-row table is not automatically a ratio table. Its paired quantities must keep one multiplicative relationship; a table that merely lists unrelated values does not.
Common mix-up
Do not add the same amount to both quantities. From 1:3 to 2:4 adds 1 to each part but changes the ratio; multiplying both by 2 gives the equivalent ratio 2:6.
Exact meaning
A ratio table is a table of equivalent pairs for two quantities. Moving to another column or row multiplies or divides both quantities by the same factor, so the ratio stays unchanged; a pair with one unit can show the unit rate.