Here are two winter temperatures from the same cold night: −8 °C and −3 °C.

The interactive shows three pairs of numbers on a number line from −10 to 10. Watch where each one sits, left or right. Further left means smaller.

Today we work these pairs of integers together, one at a time, on the board. An integer is just a whole number that can be positive or negative, with zero in the middle. For each pair, one pupil places both numbers on the line at the board; then the whole class decides which sign goes between them, < or >, and we write it up. If you are not the pupil at the board, your job is to watch the line and be ready to call the sign — that is how everyone takes part.

We will start with −4 and 1 (a negative against a positive), then −9 and −2 (two negatives, wide apart), then 0 and −5 (zero against a negative), and finally −7 and −6 — two negatives sitting right beside each other, where you have to look carefully at which is that little bit further left.

Now we place a series of integers on the −10 to 10 line, one at a time, and press Check on each placement. Between placements, the class orders a small named set aloud from smallest to biggest.