X% of Y, plus percent change.
Solve common percentage questions: what is X% of Y, X is what % of Y, and X is Y% of what?
Formula for 'X% of Y' = X ÷ 100 × Y.
These three question types cover almost every real-world percentage problem — tips, discounts, grade calculations, growth rates — so recognizing which of the three you're actually asking is usually the hardest part, not the math itself.
20% of 200 = 40.
((New − Old) / Old) × 100 — use the dedicated Percentage Change tool.
Percentage points is the raw subtraction (5% → 8% is 3 pp); percent change is the relative move ((8−5)/5 = 60%).
This usually happens with overlapping categories (someone counted in two groups) or rounding across many small percentages — worth double-checking the source data when it happens.