Mathematics for Teaching Tag: teaching negative numbers

## Tag: teaching negative numbers

### Why negative times a negative is positive

Among the ‘rules’ for working with negative numbers,  the most counter intuitive is “negative times a negative is a positive”. It is easily forgotten especially if it was learned by rote. It is also not an easy ‘rule’ to make sense of so it needs to be learned with conceptual understanding. Here’s my proposed lesson for…

### Are negative numbers less than zero?

I found this interesting article about negative numbers. It’s a quote from the paper  titled The extension of the natural number domain to the integers in the transition from arithmetic to algebra by Aurora Gallardo. The quote was transcribed from the article Negative by D’Alembert (1717-1738) for Diderot Encyclopedia. In order to be able to…

### How to scaffold algebraic thinking in teaching integers

One way to make algebra make sense to students is to show where those mathematics objects (e.g. algebraic expressions/equations/formula) come from. It will even makes sense more to students if they themselves can generate those objects. As John Mason puts it, The mechanics of algebra (algebraic manipulation) are concerned with studying the effects of combining,…