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Impress your friends with your amazing calculation skills!

Figure out how this trick works to impress everyone with your mental calculation skills.

You think you have to be a master at mental calculation to perform this trick? No way! So what’s the key then? Arithmetic, algebra? That’s for you to find out!

  • For this trick, students can find the solution with the teacher’s help. However, some of them may be able to find it on their own! Overall, this trick can be considered more advanced. It is interesting if you want to practise arithmetic operations with algebraic expressions.

  • Planning notes