Problem
A shirt's price increased from $40 to $52. What is the percentage increase?
📝Step-by-Step Solution
1
Find the increase (change)
Change = New value - Original value = $52 - $40 = $12
Increase = $52 - $40 = $12
2
Recall the percentage increase formula
Percentage increase = (Increase / Original) × 100%
% Increase = (Change / Original) × 100
3
Substitute the values
% Increase = ($12 / $40) × 100
% Increase = (12/40) × 100
4
Calculate
12 ÷ 40 = 0.3, then 0.3 × 100 = 30
0.3 × 100 = 30%
✅Final Answer
30% increase
IMPORTANT: Always divide by the ORIGINAL value, not the new value! This is the most common mistake. To find a new value after a percentage increase: New = Original × (1 + percentage/100). So $40 × 1.30 = $52.
Ready to Practice Percentages?
Generate a personalized practice test with MathQuizily. Get instant PDF downloads with answer keys.