Finding 5 percent

Quick answer

To find 5 percent of a number, first find 10 percent, then halve it. This works because 5% is half of 10%.

Learning outcome

By the end of this page, you will be able to find 5 percent of any number by calculating 10 percent and then halving it.

• You can find 10 percent of a number by dividing it by 10
• You can halve a number to find 5 percent
• You can use this method to solve real-life problems like sharing money or calculating discounts
• You can check your answer by using the reverse calculation

Why this matters

Knowing how to find 5 percent is useful in many everyday situations. For example, when shopping, you might want to know how much a 5% discount saves you. In the kitchen, you might need to measure 5% of a recipe. At school, you may need to calculate 5% for tests or projects. This skill helps you understand how percentages work, and it builds your confidence with numbers. It's also a helpful shortcut when working with bigger percentages like 15% or 25%.

How it works

Let's break down how to find 5 percent step by step:

1. Find 10 percent of the number by dividing it by 10
2. Halve that number to get 5 percent

This method works because 5% is exactly half of 10%. So if you know 10%, you just need to cut it in half.

Examples you can see

Let's try some examples with numbers you can imagine or draw.

Example 1: Finding 5% of 20

First, find 10% of 20:

• 20 ÷ 10 = 2

Now, halve that number to find 5%:

• 2 ÷ 2 = 1

So, 5% of 20 is 1.

Example 2: Finding 5% of 60

First, find 10% of 60:

• 60 ÷ 10 = 6

Now, halve that number to find 5%:

• 6 ÷ 2 = 3

So, 5% of 60 is 3.

Example 3: Finding 5% of 120

First, find 10% of 120:

• 120 ÷ 10 = 12

Now, halve that number to find 5%:

• 12 ÷ 2 = 6

So, 5% of 120 is 6.

Real-world example: Saving money at the shop

Imagine you are shopping and see a toy that costs £40. There is a 5% discount on it. How much money do you save?

• First, find 10% of £40: £40 ÷ 10 = £4
• Then, halve it to find 5%: £4 ÷ 2 = £2

You save £2 on the toy.

Try it as a mini adventure

The Great Cookie Sale Challenge

You are helping your school raise money by selling cookies. You have 100 cookies to sell, and you want to give 5% of the money to the local animal shelter. If each cookie sells for £1, how much money do you give to the shelter?

Let's solve this step by step:

1. First, find how much money you make from selling 100 cookies:
2. 100 cookies × £1 = £100
3. Next, find 10% of £100:
4. £100 ÷ 10 = £10
5. Then, halve that to find 5%:
6. £10 ÷ 2 = £5

So, you give £5 to the animal shelter.

Common mistakes

• Mistake: Forgetting to halve the 10% value
• Why it happens: Children might think 5% is the same as 10% or might get confused between 10% and 5%
• Fix: Remind them that 5% is half of 10%, so they must halve the 10% result

• Mistake: Dividing by 5 instead of dividing by 10 first, then halving
• Why it happens: Children might try to shortcut the process or not understand the relationship between 5% and 10%
• Fix: Encourage them to always find 10% first, then halve it. This method is more reliable

• Mistake: Using a calculator but not checking their work
• Why it happens: Some children might be tempted to use a calculator and not double-check
• Fix: Teach them to always verify their answer by doing a quick reverse calculation or by using a different method

Parent and carer guide

Helping your child understand how to find 5 percent can be simple and fun:

• Use everyday situations: When shopping, ask your child to find 5% of a price to see how much a discount saves
• Make it visual: Draw arrays or use counters to show 10% and then half that to show 5%
• Practice together: Try the examples from this page together. Let your child explain their thinking
• Encourage checking: Ask your child to verify their answer using the reverse calculation
• Be patient: It takes time to understand how percentages work. Celebrate small successes

Remember, children learn best when they are not stressed. Keep the learning light and fun!

Practice questions

1. What is 5% of 30?
2. What is 5% of 80?
3. What is 5% of 150?
4. What is 5% of 240?
5. What is 5% of 90?

Answers:

1. 5% of 30 = 1.5 (10% = 3, halve = 1.5)
2. 5% of 80 = 4 (10% = 8, halve = 4)
3. 5% of 150 = 7.5 (10% = 15, halve = 7.5)
4. 5% of 240 = 12 (10% = 24, halve = 12)
5. 5% of 90 = 4.5 (10% = 9, halve = 4.5)

FAQ

What does 5 percent mean?

Five percent means 5 out of every 100. It's the same as saying 5/100 or 0.05 in decimal form.

Why is finding 5% easier by halving 10%?

Because 5% is exactly half of 10%. So if you know 10%, you just need to cut it in half to get 5%.

Can I use this method for other percentages?

Yes! Once you know how to find 5%, you can use that to find 15% (5% + 10%), 20% (10% + 10%), or 25% (10% + 10% + 5%).

What if the number doesn't divide evenly by 10?

You can still use this method. For example, to find 5% of 21, find 10% of 21 (which is 2.1) and halve it (which is 1.05).

How can I check if my answer is right?

You can check by using the reverse calculation. If 5% of a number is 5, then 10% of that number should be 10, and 100% should be 100.