Anomalous cancellation

Anomalous cancellation is when you cancel out numbers in a math problem, but it doesn't quite work the way it should. Let's say you have the problem 18/24. Normally, you could cancel out the 8 and the 4 to get 9/12. But if you cancel out the 1 and the 2 instead, you get 8/4, which doesn't seem right!

This happens because the numbers in the top and bottom of the fraction have something in common, like a factor or a digit. When you cancel out that common thing, it changes the value of the problem in a way you might not expect. So, always be careful when cancelling out numbers - it might lead to an anomalous cancellation!