Number Line Checkers

Material Required: Chart paper or cardboard, pen, buttons in two different colours – 5 buttons in each colour.

Here’s a simple and delightful game which sharpens skills at adding and subtracting signed numbers. This is suitable for children in primary school.

Copy out the number line given in the figure to a convenient size. Two players play the game at a time. They get 5 buttons each in different colours, say red buttons for the first player and blue buttons for the second.

In the beginning of the game all the buttons are placed at the starting point which is zero.

Now the first player picks a card. There is a number written on it. He moves one of the red buttons to this number on the number line. Now it is the second player’s turn. She too picks up a card and a blue button on the number line on top of the number which appears in her card.

Every time a player picks a card he or she can move a fresh red button to the number on the card or can also move a button already on the number line by the number of places shown on the card. For example, if there is already a button on -5 and the card shows -7, the player can move the button to -12.

The aim of each player is to capture as many buttons as possible. Both red and blue buttons can be captured by each player.

A player can capture buttons in two ways:

• A player’s button moves past -19 0r +19. Then he or she win the button.
• One player’s button jumps over the second player’s button. Then the second player’s button is ‘killed’ and the first player gets to keep it.
• The game stops when either all red buttons or all blue buttons have left the number line.
• The person with the maximum number of buttons with her or him (both red and blue) wins.

Some additional rules:

• Two buttons cannot occupy the same position on the number line.
• If a player makes a mistake in arithmetic while moving the button, the button goes back to the starting point.
• A player can jump over his or her own button. No problem. The button stays alive.
• If a player jumps over two (or even three) of the other player’s buttons, he or she gets to keep all of them!