Copyright © University of Cambridge. All rights reserved.

## 'Factors and Multiples Game' printed from http://nrich.maths.org/

This is a game for two players.

The first player chooses a positive even number that is less than
$50$, and crosses it out on the grid.

The second player chooses a number to cross out. The number must be
a factor or multiple of the first number.

Players continue to take it in turns to cross out numbers, at each
stage choosing a number that is a factor or multiple of the number
just crossed out by the other player.

The first person who is unable
to cross out a number loses.

Here is an interactive version of the game in which you drag the
numbers from the left hand grid and drop them on the right hand
grid. Alternatively, click on a number in the left hand grid and it
will transport to the earliest empty location in the right hand
grid. You can rearrange the numbers in the right hand grid by
dragging and dropping them in position. The integer in the top
right hand corner grows with the number of factors/multiples you
have in a row.

This text is usually replaced by the Flash movie.

An extension to the game, or a suitable activity for just one
person, is suggested in the

Possible extension in the

Teachers' Notes