Percentages made simple

Last reviewed: 14 July 2026

← All articles·Study guide·6 min read

In short: Percent means "out of 100". So 25 percent is 25 out of 100, which is the same as a quarter. Learn a few key ones by heart, 50 percent is a half, 25 percent is a quarter, 10 percent is a tenth, and you can build almost any percentage from those.

Percentages are everywhere: sale signs, test scores, phone batteries. The word looks technical but the idea is simple. This guide builds it up from "out of 100" so it makes sense before any method appears.

Percent means out of 100

The word percent comes from "per hundred". So 40 percent means 40 out of every 100. If a test is marked out of 100 and your child scores 40, that is 40 percent. The percent sign is just shorthand for "out of 100".

A full battery is 100 percent, a flat one is 0 percent, and half charged is 50 percent. Children already understand percentages from screens, we are just naming it.

The ones worth knowing by heart

A handful of percentages are so common that it pays to simply know them. Everything else can be built from these.

Percentage	Is the same as	In plain words
50%	one half	split it in two
25%	one quarter	half, and half again
10%	one tenth	divide by 10
1%	one hundredth	divide by 100
100%	the whole thing	all of it

Step 1: finding 10 percent

Ten percent is the workhorse. To find 10 percent of a number, divide it by 10. This is the building block for lots of other percentages.

10% of 200 is 20
10% of 60 is 6
10% of 45 is 4.5

Step 2: build other percentages from 10 percent

Once you have 10 percent, you can reach most others by doubling, halving or adding.

20% is double 10%. So 20% of 200 is 20 doubled, which is 40.
5% is half of 10%. So 5% of 200 is half of 20, which is 10.
30% is three lots of 10%. So 30% of 200 is 3 times 20, which is 60.

To find 15%, add 10% and 5% together. For 200 that is 20 plus 10, which is 30.

Step 3: any percentage, the reliable way

For any percentage, there is one method that always works: find 1 percent first, then multiply. Find 1 percent by dividing by 100.

To find 37% of 200: 1% of 200 is 2, then 37 times 2 is 74.
To find 8% of 50: 1% of 50 is 0.5, then 8 times 0.5 is 4.

Fractions, decimals and percentages are one family

These three are just different outfits for the same amount. It helps to see them side by side.

Fraction	Decimal	Percentage
1/2	0.5	50%
1/4	0.25	25%
1/10	0.1	10%
3/4	0.75	75%

Practise together

Work these out, then check the answers below.

What is 50% of 80?
What is 10% of 90?
What is 25% of 40?
What is 20% of 150?
What is 15% of 60?
What percentage is a full battery?

Answers: 40. 9. 10. 30. 9. 100 percent.

Four golden rules

Percent means out of 100.
To find 10 percent, divide by 10. To find 1 percent, divide by 100.
Build other percentages by doubling, halving and adding.
Fractions, decimals and percentages are three ways of writing the same amount.

Frequently asked questions

When do children learn percentages?

Percentages are introduced towards the end of Key Stage 2 and developed through Key Stage 3 and GCSE, often alongside fractions and decimals. Everyday examples at home help the idea stick.

What is the easiest way to work out a percentage?

Start from 10 percent, which is just dividing by 10, then build up by doubling, halving and adding. For an exact answer to any percentage, find 1 percent by dividing by 100, then multiply.

Why do fractions, decimals and percentages keep appearing together?

Because they are three ways of writing the same thing. A half, 0.5 and 50 percent are identical. Seeing them side by side helps children switch between them with confidence.

What do you want to hear more about?

You know your child best, and we write for real families. Tell us what would help most: a topic, a worry, an age group or an exam, and we'll cover it.

Suggest a topic

Want a plan, not just tips?

Get our free year-by-year planner and affordable, expert-made packs to support your child at home for a fraction of the cost of tutoring.

Plans & free planner