How to use it
- Look for an obvious scale factor first.
- If needed, cross-multiply.
- Check that units and ratio order match.
See it in action
3/5 = x/20; denominator ×4, so numerator ×4 → x=12.
How to verify it
3/5=0.6 and 12/20=0.6.
Solve Proportions with Structure
A proportion states that two ratios are equal; scaling or cross-products can solve the missing value.