I use this mental maths activity with children aged 7 - 11. Choose a number of the week, which should be written on the board and can be referred to during numeracy lessons during the week. (The number should be suitable for the age and ability of the children).

Laminate the cards (available in PDF here ). In turn children select a card. Whatever it says the children have to work out the answer. For example if the card says - divide by 4, the children all divide the number of the week by 4. If you have individual whiteboards, all of the children can take part at the same time. Alternatively the individual who picked the card can work out the answer.

This is a particularly quick activity which can always be to hand if your mental maths activity is not planned!!