Mathematics · Grades 6–8
Percentages · Formula sheet
Rules, conditions and small examples in one printable reference.
Remember this
Percentages as fractions
Percent means per hundred. Simplify the resulting fraction.
p% = p/100
21/100 = 21/100
Find the original whole
Divide by the percentage as a decimal, not by the whole-number percent.
whole = part ÷ (p/100)
392 ÷ 0.4 = 980
Successive percentage changes
Apply each percentage to the value at that stage.
final = initial × (1 + p/100) × (1 − q/100)
7400 × 1.2 × 0.9 = 7992
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.