GCSE MATHS • HIGHER TIER
Recurring Decimals Made Simple
Recognise recurring decimals and convert accurately between recurring decimals and fractions.
Clear method
Exam practice
Worked proofs
Recurring Decimals in Four Moves
1
Recognise
Identify the digit or block of digits that repeats forever.
2
Set Up
Let x equal the recurring decimal and multiply by a suitable power of 10.
3
Subtract
Subtract the original equation so the recurring digits cancel.
4
Solve
Solve for x and simplify the resulting fraction.
What You’ll Learn
Recognise Recurring Decimals
Identify decimals with repeating digits or repeating blocks.
Use Recurring Notation
Understand dots or bars used to show recurring digits.
Convert Fractions to Decimals
Recognise fractions that produce recurring decimals.
Convert Decimals to Fractions
Use algebra to convert recurring decimals exactly.
Work with Repeating Blocks
Handle recurring decimals with one or two repeating digits.
Key Rules
Recurring Digits Repeat Forever
A recurring decimal contains a digit or block of digits that repeats indefinitely.
Use the Correct Power of 10
Multiply by 10, 100, 1000 and so on to move one complete recurring block.
Align the Recurring Digits
The repeating digits must line up before subtracting the equations.
Subtract to Cancel
Subtract the original equation from the multiplied equation to remove the recurring part.
Worked Proof: Recurring Decimals
Step-by-Step Method
- 1. Identify the digit or block of digits that repeats.
- 2. Let x equal the recurring decimal.
- 3. Multiply both sides by 10, 100 or another suitable power of 10.
- 4. Subtract the original equation to cancel the recurring digits.
- 5. Solve for x and simplify the fraction fully.
More Worked Examples
4
Convert 0.666... into a fraction .
Let x = 0.666...
10x − x = 6
9x = 6
- Common GCSE Mistakes
- Algebra: Do not forget to introduce x when converting a recurring decimal to a fraction.
- Power of 10: Choose the power that moves one full recurring block.
- Simplifying: Always simplify the final fraction where possible.
- Decimal type: Do not confuse terminating decimals with recurring decimals.
- Exam Tips
- Identify exactly which digit or block repeats before starting.
- For one recurring digit, multiplying by 10 is often appropriate.
- For two recurring digits, multiplying by 100 is often appropriate.
- Write both equations clearly before subtracting.
- Check that the recurring parts line up and cancel.
- Simplify the final fraction fully.
Skills Used in Recurring Decimals
Fractions
Decimals
Recurring Notation
Algebra
Powers of 10
Subtraction
Simplifying Fractions
Higher Tier Number Skills
Ready to Practise?
Watch the Recurring Decimals Tutorial
Step-by-step walkthroughs of Recurring Decimals with clear methods and exam tips.
Frequently Asked Questions
A recurring decimal is a decimal in which one or more digits repeat forever.
The source explains that a dot or bar can be placed above the recurring digit or digits.
Yes. The source states that every recurring decimal can be written exactly as a fraction.
It shifts one complete recurring block so subtraction can remove the repeating decimal part.
Use a power of 10 that moves the full two-digit block, as shown in the source examples using 100.
Yes. Simplifying the resulting fraction is part of the method and is highlighted in the revision checklist.