I love simple mathematics games that can be reused over and over. Also ones that combine strategy and fluency, such as this multiplication game.
Fairly self explanatory - two players, each take turns to choose a number from the top and the bottom and multiply them together. The answer will be in the grid, and the aim is to get four in a row on the grid.
One observation is watching students reverse their thinking, "Oh I need 3204, that is an even number and it ends in 4, which numbers will help me achieve that result"
