Theory
A recurring decimal has a digit or block of digits that repeats forever. The dots or repeated digits mean the decimal does not stop.
The aim is to turn the recurring decimal into an exact fraction, not a rounded decimal.
Let x equal the recurring decimal. Then multiply by 10, 100, or 1000 so the repeating block lines up underneath itself.
Use 10 when one digit repeats, 100 when two digits repeat, and 1000 when three digits repeat.
Subtract the smaller equation from the larger equation. The recurring decimal parts cancel, leaving a normal equation.
Solve for x and simplify the fraction. Edexcel marks usually reward the setup, the subtraction, and the simplified fraction separately.
Key ruleLine up the recurring block before subtracting.