Money and Real-Life Problems

The CSSE 11+ maths paper is packed with questions set in real-life contexts: shopping, travel, recipes, wages, and more. These questions test your ability to apply maths skills to practical situations. This lesson covers the key types of money and real-life problems you will encounter, with plenty of worked examples.

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Working with Money

Key Facts

Fact
£1 = 100p
Always line up the decimal point when adding or subtracting money
Write money answers with exactly 2 decimal places (e.g. £3.50, not £3.5)

Adding and Subtracting Money

A book costs £8.75 and a pen costs £2.49. What is the total cost?

• £8.75 + £2.49 = £11.24

Ella has £50. She spends £23.67. How much does she have left?

• £50.00 - £23.67 = £26.33

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Giving Change

Worked Example: Tom buys 3 sandwiches at £3.85 each. He pays with a £20 note. How much change does he get?

Step 1: Total cost = 3 × £3.85 = £11.55

Step 2: Change = £20.00 - £11.55 = £8.45

CSSE Tip: On the CSSE, change questions almost always require you to calculate the total first, then subtract from the amount paid. Watch for questions that ask you to buy different quantities of different items.

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Best Buy / Value for Money

These are classic CSSE questions. You calculate the unit price (price per single item) and compare.

Shop A: 4 oranges for £2.20. Shop B: 6 oranges for £3.00. Which is better value?

• Shop A: £2.20 ÷ 4 = 55p per orange
• Shop B: £3.00 ÷ 6 = 50p per orange
• Shop B is better value (cheaper per orange)

Worked Example: Three Options

Small box: 200 g of cereal for £1.60. Medium box: 500 g for £3.50. Large box: 1 kg for £6.40. Which is the best value?

• Small: £1.60 ÷ 200 = 0.8p per gram
• Medium: £3.50 ÷ 500 = 0.7p per gram
• Large: £6.40 ÷ 1,000 = 0.64p per gram
• Large box is the best value

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Profit and Loss

Profit is the difference between what you sell for and what you paid.

Profit = Selling price - Cost price

Loss occurs when the selling price is less than the cost price.

Worked Example

A trader buys 60 mugs at £2.50 each. She sells 45 at £4.00 each and the remaining 15 at £1.50 each (at a discount). What is her overall profit?

Step 1: Total cost = 60 × £2.50 = £150.00

Step 2: Income from 45 mugs = 45 × £4.00 = £180.00

Step 3: Income from 15 mugs = 15 × £1.50 = £22.50

Step 4: Total income = £180.00 + £22.50 = £202.50

Step 5: Profit = £202.50 - £150.00 = £52.50

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Percentage Increase and Decrease

Finding a Percentage of an Amount

Find 15% of £80

• 10% of £80 = £8.00
• 5% of £80 = £4.00
• 15% of £80 = £8.00 + £4.00 = £12.00

Percentage Increase (e.g. Price Rise, VAT)

A coat costs £60. The price increases by 20%. What is the new price?

• 20% of £60 = £12
• New price = £60 + £12 = £72

Percentage Decrease (e.g. Sale, Discount)

A laptop costs £450. It is reduced by 15%. What is the sale price?

• 15% of £450 = £67.50
• Sale price = £450 - £67.50 = £382.50

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Wages and Earnings

Worked Example

Lucy earns £9.50 per hour. She works 8 hours on Monday and 6 hours on Tuesday. How much does she earn?

• Monday: 8 × £9.50 = £76.00
• Tuesday: 6 × £9.50 = £57.00
• Total = £76.00 + £57.00 = £133.00

Overtime