Use the part-to-whole ratio as a cross-check
12:60 simplifies to 1:5. Reading that reduced ratio as a decimal and multiplying by 100 gives the same percentage, which is a useful check on the direct formula.
- 1.Form the ratio 12 ÷ 60.
- 2.12 ÷ 60 = 0.2.
- 3.0.2 × 100 = 20%.