Are negative numbers important

Answer 1

Negative numbers are extremely important for indicating deficit.

If I have a certain number of bricks, and a certain number needed for a house, then if I do a simple sum and find that the number of bricks left over after building the house will be -320, then I know I don't have enough bricks, and need to buy 320 before the house can be built.

If I get a bank statement that says my current balance is -£89 then this means I owe the bank £89.

If I work out the percentage change in the number of people dying from flu each year, and it comes to -1.4%, then I know fewer and fewer people are dying from flu, and whatever action is being taken seems to be working.

These are just 3 examples in which negative numbers are very important.