Everyone likes surprises. They've got that Venus flytrap quality. They arrest our attention, widen our pupils and get us thinking. One way of surprising children is to set traps for them to fall into. No, don't call the authorities yet because we're talking maths traps. Maths statements can be very effective in trapping children. For example, 3 and 5 are consecutive numbers.
Children might argue that this isn't true but 3 and 5 are consecutive odd numbers. They're also consecutive primes. The value of the 2 in 825 is 2.
Most children will disagree and say the 2 is worth 20 without hesitation.
Well, its place value is two 10s but its face value is 2. It depends which value we are talking about. Multiplying by 10 makes a number 10 times bigger.
Some might fall for this and agree. But what about 0 x 10?
Carefully laid statement traps can raise a few eyebrows, start a bit of head scratching and deepen understanding. Try some yourself and teach children a lesson they'll never forget
John Dabell is a numeracy consultant and teacher trainer