*By William McCallum*

“I’m afraid I can’t explain myself, sir.

Because I am not myself, you see?” Alice in Wonderland.

The idea of equivalence in mathematics is tricky for learners, because when we talk about two things being equivalent, for example the fractions $\frac35$ and $\frac6{10}$, we are emphasizing two contradictory things: Continue reading “Fractions: Units and Equivalence”