Zero is not the end of the line
A negative number is a number less than zero. A minus sign in front tells you which side of zero it belongs on: −3 means negative three.
A temperature of −3°C is three degrees below zero. Numbers such as −1, −2 and −3, together with zero and the positive whole numbers, are called integers. OpenStax explains their positions on a number line.
Why −2 is greater than −5
Imagine equally spaced marks labelled −5, −4, −3, −2, −1, 0, 1, 2. Values increase as you move right.
Although 5 is greater than 2, −2 is greater than −5. It sits farther right. A temperature of −2°C is warmer than −5°C, even though both are below zero.
Zero is neither positive nor negative. And negative numbers do not stop at −5: you can keep travelling left.
A small rise through zero
Suppose an imagined temperature starts at −3°C and rises by 5°C. Three degrees of that rise take it to zero. The remaining two take it to 2°C.
That is −3 + 5 = 2. The starting minus sign gives a position; the plus sign tells you to add.
Same distance, opposite sides
The numbers −4 and 4 are both four steps from zero, on opposite sides. They are opposites. This is about position, rather than a claim that one is farther from zero.
If the starting point feels unfamiliar, return to counting and zero. You can use the same evenly spaced line and extend it left.