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Let’s say you need to buy potatoes and want to get the best deal. At the farm shop, a 12.5 kg bag costs £9. At the supermarket, a 2.5 kg bag costs £1.83. Which place offers the better value for money? Let’s work it out step by step!
Step 1: Find the Cost Per Kilogram
To compare the prices fairly, we need to find the price per kilogram at each shop. This means dividing the total price by the number of kilograms in each bag.
Farm Shop Calculation
- Price: £9
- Weight: 12.5 kg
Cost per kilogram = £9 divided by 12.5
Cost per kilogram = 9 ÷ 12.5 = 0.72
So, at the farm shop, each kilogram of potatoes costs 72p.
Supermarket Calculation
- Price: £1.83
- Weight: 2.5 kg
Cost per kilogram = £1.83 divided by 2.5
Cost per kilogram = 1.83 ÷ 2.5 = 0.732
So, at the supermarket, each kilogram of potatoes costs about 73p (rounded to the nearest penny).
Step 2: Compare the Costs Per Kilogram
Here’s what we found:
- Farm shop: 72p per kg
- Supermarket: 73p per kg
Step 3: Decide Where the Better Value Is
The lower the cost per kilogram, the better the value. The farm shop offers potatoes at 72p per kg, which is slightly cheaper than the supermarket at 73p per kg.
Final Answer
The potatoes are the better value at the farm shop.
Why Is This Useful?
Working out the cost per unit (in this case, per kilogram) is a great way to compare prices, especially when the packs are different sizes. This skill is useful not only in maths exams but also in real life whenever you’re shopping and want to save money.
If you find these sorts of calculations tricky, remember that maths tuition online for GCSE students can help you master comparing prices, unit costs, and many more practical maths skills.
Next time you’re at the shop, try working out the price per kilogram or per litre before you buy. You’ll make smarter choices and get the best value for your money!
