Count On

Explorer:

• 
  
  • Maths and Magic
  • Patterns
  • Randomiser
  • Number
  • Primes, Factors and Divisibility
  • The Fabulous Fractal Factory
• 
  
  • The Wise Wizz of Woo
  • Diversions
  • Origami
  • Puzzle of the Day
  • Fractions
  • Online Stories

Puzzle of the Day

These puzzles are also printed in Eight days a week, a booklet published by the Association of Teachers of Mathematics.

Start at 80. You are allowed to add 11 and take 7 as many times as you like. Can you make 70? Try some other starts and finishes of your own. Is it always possible to finish where you choose from any start?

Answer: 80+11-7-7-7. It is always possible