Items needed:
A piece of paper (we have used A5)
2 felt tip pens in different colours
How to play:
With the paper landscape write numbers 1-10 along the top using the first colour of pen. Down the left side of the paper write numbers 11, 21, 31, 41. On the right side write numbers 20, 30, 40, 50. Make sure the numbers are evenly spaced. You can also go as high up as you like to make the game more difficult.
Draw lines between the numbers to make a grid (as pictured). Fill in a few of the numbers to get the game started. Then ask the child playing to fill in all the numbers that are missing until the grid is complete.
Older children might enjoy filling it all out themselves, whereas with younger children, working together is key.
Once the grid is completed you can keep it for future reference.