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.

A street of houses numbered from 1 to 100 inclusive is to be numbered with new brass numerals. How many of the digit \"2\" would be needed to complete the job?

Answer: 20