Here's another cool math trick to teach your kids! Get them to try it with lots of different numbers to sneak in some extra math practice, whilst amazing them that the answer is always 5!
If the answer isn't 5, then a calculation mistake was made and so needs to be redone. You could get your students to show the math on a piece of paper to check.
A fun and challenging activity that you could give your students is to get them to try and explain how this trick works.
Example of using this trick:
Step 1: I choose 100
Step 2: Double it = 200
Step 3: Add 10 = 210
Step 4: Halve it = 105
Step 5: 105 - (100)