Book Codes

Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?

The Remainders Game

A game that tests your understanding of remainders.

Newspaper Sheets

Weekly Problem 29 - 2011
From only the page numbers on one sheet of newspaper, can you work out how many sheets there are altogether?

Neighbours

Stage: 2 Challenge Level:

In a square in which the houses are evenly spaced around the outside, numbers $3$ and $10$ are opposite each other.

What is the smallest number of houses in the square?

What is the largest possible number of houses in the square?