Set up a square, marked out in the four corners of the hall, and marked with numbers 1,2,3,4 respectively.
On the floor of the hall, spread out, will be 4 sets of numbers from 1-8 (so there will be four 1’s, four 2’s etc in the hall). Pupils will jog around the hall in and out of numbers.
The teacher shouts a number between 1 and 8. At this, the pupils have to pick up whatever number they are closest to, and using the numbers in the corners, have to get the number the teacher shouted using adding or subtraction, e.g. if the teacher shouts 3 and the pupil picks up number 5, then that pupil must run to the corner numbered 2, as 5 minus 2 equals 3.
There will be a section marked out in the middle of the hall for those that can’t be solved, e.g. if the teacher shouts 1 and the pupil picks up number 1, then they can’t make 1 by adding or subtracting numbers 1, 2, 3 or 4.