This is a set of four sheets of calculations, with each sheet having 5 ‘fibs’ that aren’t correct. The children must use their number knowledge to spot the calculations that aren’t true and circle them.
Base Camp = smaller numbers, just addition.
Hill Climber = smaller numbers, addition and subtraction.
Mountaineer = larger numbers, addition and subtraction.
Everest = Calculations such as 12+3 = 19-4 where each side needs to be checked to see if the calculation balances.
What I particularly like about this activity is that the children know how many mistakes there are, which helps them work out if they still have more mistakes to find or if they have found too many! Also to check their answers you only need to check they have put the circles in the right place, which means you can do a lot of checking quickly in the lesson and then move them up a level if you have time.
This makes for a good stand-alone lesson where you review various mental maths skills first.