Resources tagged with: Disproof by counterexample

There are 3 NRICH Mathematical resources connected to Disproof by counterexample, you may find related items under Thinking Mathematically.

Broad Topics > Thinking Mathematically > Disproof by counterexample

Legs Eleven

Age 11 to 14
Challenge Level

Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?


Age 7 to 11

These tasks provide opportunities for learners to get better at proving, whether through proof by exhaustion, proof by logical argument, proof by counter example or generic proof.

On the Importance of Pedantry

Age 16 to 18

A introduction to how patterns can be deceiving, and what is and is not a proof.