Paper 2 calculator

Question 1

How do you convert recurring decimals into fractions?

Answer 1

• 1) write the decimal as

n = e.g. 0.27 (27 have dots above) recurring = 0.27272727)

• 2) Multiply the recurring decimal by 100 (or 10 if 1 digit recurring or 1000 is 3 digits recurring)
  e. g. 100n = 27.272727
• 3) Subtract n to remove the recurring part
  e. g. -n = -0.272727

hence 99n = 27 (or 9n if 1 digit or 999n is 3 digits)

• 4) divide both sides by 99
  e. g. 99n = 27

n= 27/99 = 3/11

Question 3

How do you convert fractions into recurring decimals?

Answer 3

Use the bus stop method (divide numerator by denominator)