Discount Signs maths mission

Quick answer

You can use discount signs to practice percentages in a fun way – like working out how much money you save when something is 20% off or how much you pay after a 15% discount.

Learning outcome

By the end of this page, you will be able to work out how much money you save or pay when you see discount signs, using simple percentage calculations that are useful in real-life shopping.

• I can find 10% of a number by dividing by 10
• I can calculate how much a discount saves me
• I can work out the final price after a discount
• I can use real shopping examples to solve percentage problems

Why this matters

Shopping with discounts helps you understand percentages in a real and exciting way. When you're out shopping, you'll see signs that say "20% off", "Save 10%", or "Half price". Knowing how to work out what these mean helps you save money and feel confident about your maths. This skill will also help you in school when you learn more about percentages, fractions, and decimals.

How it works

Let's break down how to work out a discount step by step:

1. Find the original price – this is how much something costs before any discount.
2. Work out the percentage – this tells you what part of the price you're saving.
3. Calculate the discount amount – multiply the original price by the percentage (in decimal form).
4. Subtract the discount from the original price – this gives you the final price you pay.

Examples you can see

Let’s look at some real examples of how discount signs work:

Example 1: 25% off a £40 toy

Step 1: Original price = £40

Step 2: 25% means 25 out of 100, so 25 ÷ 100 = 0.25

Step 3: Discount = £40 × 0.25 = £10

Step 4: Final price = £40 – £10 = £30

So you save £10 and pay £30 for the toy!

Example 2: 30% off a £60 jumper

Step 1: Original price = £60

Step 2: 30% = 30 ÷ 100 = 0.30

Step 3: Discount = £60 × 0.30 = £18

Step 4: Final price = £60 – £18 = £42

You save £18 and pay £42 for the jumper.

Example 3: 50% off a £24 book

Step 1: Original price = £24

Step 2: 50% = 50 ÷ 100 = 0.50

Step 3: Discount = £24 × 0.50 = £12

Step 4: Final price = £24 – £12 = £12

You save £12 and pay £12 for the book.

Try it as a mini adventure

Adventure: The Shopping Mission

You are a detective on a mission to find the best deals in town. You have a list of items and their original prices. You must calculate how much you save and how much you pay after each discount. Let’s go!

1. Item 1: £100 jeans, 10% off
2. Item 2: £50 T-shirt, 20% off
3. Item 3: £80 shoes, 25% off
4. Item 4: £30 hat, 50% off
5. Item 5: £60 scarf, 15% off

Challenge: Work out how much you save and how much you pay for each item. You can use the steps we’ve learned or draw a picture to help you.

Item 1: £100 jeans, 10% off

10% of £100 = £10

You save £10, so you pay £90.

Item 2: £50 T-shirt, 20% off

20% of £50 = £10

You save £10, so you pay £40.

Item 3: £80 shoes, 25% off

25% of £80 = £20

You save £20, so you pay £60.

Item 4: £30 hat, 50% off

50% of £30 = £15

You save £15, so you pay £15.

Item 5: £60 scarf, 15% off

15% of £60 = £9

You save £9, so you pay £51.

Common mistakes

• Mistake: Thinking 10% off means you pay 10% of the price.
• Why it happens: Confusing "off" with "pay".
• Fix: Remember that 10% off means you save 10% of the price, so you pay 90% of the price.

• Mistake: Using 0.1 instead of 0.10 for 10%.
• Why it happens: Not understanding decimal places.
• Fix: Write 10% as 0.10 to make it clear that it's 10 hundredths.

• Mistake: Forgetting to subtract the discount from the original price.
• Why it happens: Rushing through the steps.
• Fix: Always double-check that you’ve subtracted the discount to find the final price.

Parent and carer guide

Here’s how you can help your child practice this shopping maths mission:

• Go shopping together and let your child find discount signs. Ask them to work out how much is saved.
• Use a calculator to check answers, but encourage mental maths first.
• Ask questions like: "How much would you save on a £20 item with 20% off?"
• Make it fun by turning it into a game – who can find the best deal?
• Use real items at home to practice, like a £10 toy with 30% off.

Practice questions

1. What is 10% of £50?
2. A £30 item is 20% off. How much do you save?
3. A £40 item is 25% off. What is the final price?
4. How much is saved on a £60 item with 15% off?
5. What is the final price of a £80 item with 30% off?

Answers:

1. £5
2. £6
3. £30
4. £9
5. £56

FAQ

What is a discount?

A discount is a reduction in the price of something, usually shown as a percentage.

How do I work out a discount?

You multiply the original price by the percentage (as a decimal) to find the discount amount, then subtract that from the original price.

Why do shops use percentages for discounts?

Percentages help shoppers quickly see how much they save and compare prices easily.

Can I use a calculator for discounts?

Yes! You can use a calculator to check your answers, but try doing the maths first to build your skills.

How can I practice this at home?

Look at items in your home or at a shop and work out how much they save or how much you pay after a discount.