💰 Percentage of an Amount

Calculate parts of quantities using percentages

🎯 What You'll Learn

Calculate percentages of amounts using different methods
Convert percentages to decimals or fractions for calculations
Solve real-world percentage problems
Use mental math strategies for common percentages

✏️ Explanation

To find the percentage of an amount, convert the percentage to a decimal or fraction and multiply.

Percentage ÷ 100 × Amount = Result

You can also think of it as: Decimal × Amount = Result

🔍 Why It Matters

Useful for working out sales, discounts, taxes, and exam results. Finding percentages of amounts is essential for shopping, finance, and everyday calculations like calculating tips, discounts, and interest.

🧭 Percentage of a Quantity

Follow this simple 3-step process to find any percentage of an amount:

Convert % to Decimal

20% = 0.2

→

Multiply by Amount

0.2 × £50 = £10

→

Get Result

£10

Convert → Multiply → Result

✏️ Worked Example: 20% of £50

Given: Find 20% of £50

Step 1: Convert percentage to decimal

20% = 20 ÷ 100 = 0.2

Step 2: Multiply by the amount

0.2 × £50 = £10

Answer: 20% of £50 = £10

🧮 Percentage Calculator

Calculate percentage of an amount:

% of =

Convert percentage to decimal

20% = 20 ÷ 100 = 0.2

Multiply by the amount

0.2 × 150 = 30

Final answer

20% of 150 = 30

Answer:

20% of 150 is 30

🔢 Practice Exercises

1. What is 10% of 80?

2. What is 25% of 120?

3. What is 15% of 200?

4. What is 5% of 400?

5. What is 30% of 90?

⚠️ Common Mistakes

Forgetting to convert the percentage first - trying to multiply 20 × 50 instead of 0.2 × 50
Using incorrect operations (e.g. dividing instead of multiplying)
Confusing percentage OF an amount with finding what percentage one number is of another

✨ Quick Summary

Convert % → Decimal/Fraction → Multiply.