Write equivalent fractions, simplify to lowest terms, switch between mixed numbers and improper fractions, and order fractions. It is a Foundation topic, aimed at grade 1. Free questions with answers are on this page. Worked examples show each line before you try the questions.
Two fractions are equivalent when they name the same amount of the whole. Multiply or divide the top and the bottom by the same number and the value does not change: 53=2012. Simplifying is the reverse — keep dividing until the top and bottom share no common factor other than 1. 6045=43, not 129, because you can still divide by 3.
A mixed number 283 is two wholes and three eighths. Each whole is 88, so 283=816+3=819. The other way, 517=352 because 17÷5=3 remainder 2.
To order fractions, give them a common denominator and compare numerators. Cross-multiplying a×d against c×b is a shortcut when you only have two fractions to compare.
Objectives
Name the numerator and the denominator.
Simplify a fraction by dividing top and bottom.
Find a unit fraction of a whole number.
Key points
Find equivalent fractions by multiplying or dividing top and bottom by the same number.
Simplify a fraction fully by dividing by the highest common factor.
Change a mixed number to an improper (top-heavy) fraction and back again.
Order fractions by writing them with a common denominator.
Worked examples
Example 1
Simplify the fraction 2/4.
2 marks
The highest common factor of 2 and 4 is 2.
2 ÷ 2 = 1 and 4 ÷ 2 = 2.
The result is 1/2.
Answer: 1/2
Common slips
Slip: The highest common factor of 2 and 4 is 1. The common factor 1 is always there, but it is not the highest one.
Slip: 2 ÷ 2 = 1 and 4 stays 4. The top and the bottom must be divided by the same number, or the value changes.
Slip: The result is 5/2. That does not match the working above it.
Example 2
What is 2/3 of 15?
2 marks
15 ÷ 3 = 5.
5 × 2 = 10.
The result is 10.
Answer: 10
Common slips
Slip: 15 × 3 = 45. That uses multiplication, but this step needs division.
Slip: 5 + 2 = 7. That uses addition, but this step needs multiplication.
Slip: The result is 14. That does not match the working above it.
Example 3
Simplify the fraction 12/16.
3 marks
The highest common factor of 12 and 16 is 4.
12 ÷ 4 = 3 and 16 ÷ 4 = 4.
The result is 3/4.
Answer: 3/4
Common slips
Slip: The highest common factor of 12 and 16 is 2. That is a common factor, but it is not the highest, so the fraction would not be fully simplified.
Slip: 12 ÷ 4 = 3 and 16 stays 16. The top and the bottom must be divided by the same number, or the value changes.
Slip: The result is 7/4. That does not match the working above it.
Questions and answers
GCSE Maths writing, simplifying & ordering fractions questions and answers. Try each one, then open the answer. Easy questions come first.
Question 1 Easy2 marks
What is 1/4 of 24?
Show answer
Answer: 6
24 ÷ 4 = 6.
The result is 6.
M1 — 24 ÷ 4 = 6.
A1 — Answer 6
Question 2 Easy2 marks
Simplify the fraction 5/10.
Show answer
Answer: 1/2
The highest common factor of 5 and 10 is 5.
5 ÷ 5 = 1 and 10 ÷ 5 = 2.
M1 — The highest common factor of 5 and 10 is 5.
A1 — Answer 1/2
Question 3 Medium2 marks
What is 2/5 of 45?
Show answer
Answer: 18
45 ÷ 5 = 9.
9 × 2 = 18.
M1 — 45 ÷ 5 = 9.
A1 — Answer 18
Question 4 Medium2 marks
Simplify the fraction 6/10.
Show answer
Answer: 3/5
The highest common factor of 6 and 10 is 2.
6 ÷ 2 = 3 and 10 ÷ 2 = 5.
M1 — The highest common factor of 6 and 10 is 2.
A1 — Answer 3/5
Question 5 Hard2 marks
What is 3/5 of 55?
Show answer
Answer: 33
55 ÷ 5 = 11.
11 × 3 = 33.
M1 — 55 ÷ 5 = 11.
A1 — Answer 33
Question 6 Hard2 marks
Simplify the fraction 18/30.
Show answer
Answer: 3/5
The highest common factor of 18 and 30 is 6.
18 ÷ 6 = 3 and 30 ÷ 6 = 5.
M1 — The highest common factor of 18 and 30 is 6.
A1 — Answer 3/5
Question 7 Exam-style3 marks
What is 3/8 of 64?
Show answer
Answer: 24
64 ÷ 8 = 8.
8 × 3 = 24.
The result is 24.
M1 — 64 ÷ 8 = 8.
M1 — 8 × 3 = 24.
A1 — Answer 24
Common mistakes
Most lost marks on this topic are one slip.
Cancelling a number from the top only.
Whatever you divide the top by, divide the bottom by as well.
Reading the denominator as the number you have.
The bottom tells you the size of each part.
Thinking a larger denominator means a larger fraction.
More equal parts means each part is smaller.
Spot the slip
How many quarters make one whole?
4
2
1
Show the slip
4 Four quarters make one whole.
Exam tips
Be ready to do this without a calculator. Paper 1 is the non-calculator paper.
If the question says “show that”, the result is given. The marks are for the steps that reach it.
The method is the same on AQA-style and Edexcel-style papers.
Always give a fraction answer in its simplest form unless the question tells you otherwise — a final unsimplified fraction can lose the accuracy mark.
In an ordering question, write each equivalent fraction clearly with the common denominator; that working is where the method marks are.
Printable worksheet
The same questions are in a PDF you can print. Answers start on a later page.