Finding Percent of a Number
Finding a percent of a number means finding a part of that number that equals the given percent. It's like asking: "What is this fraction of the whole?"
Key Idea: "20% of 150" means finding the value equal to 20 hundredths of 150. The answer is 30.
📐 The Main Formula
Percent of Number = Number × (Percent ÷ 100)
To find a percent of a number:
- Convert the percent to a decimal or fraction
- Multiply by the number
Example: 25% of 80 = 80 × 0.25 = 20
🔢 Two Methods
Using Decimals
- Divide percent by 100
- Multiply by the number
15% of 200:
15 ÷ 100 = 0.15
200 × 0.15 = 30
Using Fractions
- Write percent as fraction over 100
- Simplify if possible
- Multiply by the number
25% of 80:
25/100 = 1/4
1/4 × 80 = 20
⚡ Quick Mental Math Shortcuts
50%
÷ 2
25%
÷ 4
10%
÷ 10
1%
÷ 100
20%
÷ 5
5%
÷ 20