Skip to main content


Discover how you can find the sum of four secret numbers by counting cards!

You could clearly see the magician counting the cards, but how did he find the sum of the numbers? He didn’t know what the numbers were!

Can you understand what the magician is doing through trial and error? There’s not other way since the magician won’t reveal his trick! Pursue this magical adventure with your friends; this way, you can make several attempts faster. This trick can be performed in various ways, which makes it even more interesting.

  • This trick is perfect to do with the whole class since up to 4 students can participate. Let your students find the solution by themselves!

  • The students must master place value to be able to recreate this trick, which is great for practising mental calculation.

  • Planning notes