Put down your tablet, turn off the computer and hide that calculator. It’s time for some mental maths games!
Serve a ‘number’ under 100. Your partner must return the serve by responding with the number that would make your total 100 – within a strict 5 second time limit. e.g. if player 1 serves 45, then player 2 would need to respond 55. You can alter the difficulty by making the total number smaller: 20, 50, 1000 etc.
Give your partner a start number and ask them to count backwards or forwards. They must say the next 5 numbers in the sequence. If they manage it they get a ‘high 5’. You can make it more challenging by varying the jumps .e.g. count backwards from 55 in sixes.
Think of a number and keep it to yourself. Your partner will then ask questions to work out what it is. e.g. “Is it an even number?”, “Is it a multiple of 5?”
Come up with ‘crazy problems’ together and then try to solve them! e.g. How old am I in days? How many times does your heart beat per day?