Percent of a Number: Finding 20% of 50 (6th Grade)

What is it?

Percent means "out of 100", so 20% is 20 out of every 100, or 20/100. To find a percent of a number, turn the percent into a friendly fraction and take that part of the number. 20/100 simplifies to 1/5, and 25% is 1/4. Another way is to find 10% first by dividing by 10, then scale up. The same idea handles sale prices and tips.

Step by step: 20% of 50

1. Find 20% of 50. Percent means out of 100, so 20% = 20/100.
2. Simplify the fraction: 20/100 = 1/5.
3. Take 1/5 of 50. That is 50 ÷ 5 = 10.
4. So 20% of 50 is 10.
5. Check with 10%: 10% of 50 is 50 ÷ 10 = 5. 20% is two tens, so 2 × 5 = 10.

Common mistakes

• Treating 20% as the number 20. 20% of 50 is not 20.
• Dividing by the percent number. 50 ÷ 20 is not the answer; use the fraction, 1/5.
• Forgetting that a percent of a number is a part of it, so it is less than the number when the percent is under 100.

Your turn

Here is a problem to try. Pause and let your child work it out before you check.

What is 25% of 80?

Answer: 20. 25% = 25/100 = 1/4, and 80 ÷ 4 = 20.

Practice at home

Look for percents in real life: a sale sign, a battery icon, a tip. Pick a price like $40 and find 10% by moving the decimal one place, then 20% by doubling it. Ask your child which friendly fractions match 50%, 25% and 10%.