Everyday Maths Guides
Clear guides to percentages, VAT, discounts and unit prices — the everyday calculations that come up again and again.
Use the Everyday Maths Guides
Percentages appear everywhere — pay rises, discounts, interest rates, tax — and the calculation trips people up more than it should. This guide covers the four core methods: finding a percentage of a number, finding what percentage one number is of another, percentage increase and percentage decrease — with plain examples for each.
Read guide →Percentage Increase vs Percentage Difference: What's the Difference?
Percentage increase measures how much something has gone up relative to its starting point. Percentage difference compares two values with no defined starting point. They look similar but give different answers — this guide explains when to use each.
Read guide →How to Add or Remove VAT: Standard, Reduced and Zero Rates
Adding VAT is not simply multiplying by 20%. Removing it is not dividing by 20% either. This guide explains the correct method for adding and removing VAT at the 20% standard rate and 5% reduced rate — and lists what falls into each category.
Read guide →How to Work Out a Discount: Sale Price, Saving and Original Price
Whether you are working out a sale price, the saving in pounds, or the original price from a discounted one, the method is different each time. This guide covers all three calculations with examples you can do in your head or on paper.
Read guide →How to Compare Unit Prices and Find the Best Value
Supermarkets are required to display unit prices — but many people do not know how to use them, especially when sizes and units differ. This guide explains how to standardise and compare prices per 100g, per litre or per unit to find the best value every time.
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