Key Points

✓A percentage is a fraction out of 100.
✓The symbol for percent is %.
✓To convert a percentage to a decimal, divide by 100.
✓To find a percentage of a number, multiply the decimal form of the percentage by the number.
✓Percentages are used to represent parts of a whole.

A percentage is a way of expressing a number as a fraction of 100. The word 'percent' means 'per hundred'. So, when you see something like '50%', it means 50 out of every 100. Percentages are used all the time to describe things like discounts, test scores, and even the amount of ingredients in a recipe. To find a percentage of a number, you can convert the percentage to a decimal or a fraction and then multiply. For example, to find 25% of 80, you can change 25% to 0.25 and multiply it by 80. This gives you 20. Percentages are a useful tool for comparing different amounts and understanding proportions.

Worked Example

What is 30% of 50?

Step 1: Convert the percentage to a decimal: 30% = 30/100 = 0.30
Step 2: Multiply the decimal by the number: 0.30 * 50
Step 3: Calculate the result: 0.30 * 50 = 15

Answer: 30% of 50 is 15.

Try It Yourself

1. What is 10% of 100?

2. A store is having a 20% off sale. If an item originally costs $40, what is the sale price?

3. If 60% of a number is 42, what is the number?

Watch Out For These Mistakes

Forgetting to convert the percentage to a decimal or fraction before multiplying.
Calculating the percentage of the wrong number.
Adding a percentage when you should be subtracting (or vice versa).