GCSE · Fractions & decimals

Recurring decimals and fractionsExam-style questions

Why the ×10ⁿ-and-subtract trick turns any recurring decimal into a fraction, how to choose the right multiplier, and which fractions terminate (and why the denominator's primes decide it).

14 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 3Level 4Level 5
  1. 1
    Use algebra to show that 0.4˙2˙+0.35˙7˙=m550.\dot{4}\dot{2} + 0.3\dot{5}\dot{7} = \dfrac{m}{55}, where mm is an integer.

    (3 marks)
    Level 5 · 3 marksTry it
  2. 2
    x=0.7˙x = 0.\dot{7} and y=0.16˙3˙y = 0.1\dot{6}\dot{3}

    Express xyxy as a fraction in its simplest form.

    (5 marks)
    Level 5 · 5 marksTry it
  3. 3
    Prove algebraically that the recurring decimal 2.13˙6˙2.1\dot{3}\dot{6} can be written as 4722\dfrac{47}{22}
    Level 5 · 3 marksTry it
  4. 4
    Prove algebraically that the recurring decimal 1.2˙0˙7˙1.\dot{2}\dot{0}\dot{7} can be written as 134111\dfrac{134}{111}
    Level 5 · 3 marksTry it