What to line up
Match first quantity to first quantity, second to second, and keep units consistent. Swapping order or units makes equal ratios look unequal (or the reverse). Variables covers both ideas together.
Related lessons
See also this lesson and this one for related setups you can place side by side.
Same ratio, different look
Example: 3:2 and 6:4 describe the same ratio; 3:2 and 2:3 do not. Write both as “first quantity : second quantity” before you decide if they match.
Check
Aligned setup Mismatched setup
Same numbers
Core lesson
Go deeper: Variables. Use the calculators below with your own loan or bill numbers, not only the examples on this page.