You use minus to show that one number or quantity is being subtracted from another.

Minus before a number or quantity means that the number or quantity is less than zero.

Teachers use minus in grading work in schools and colleges. 'B minus' is not as good as 'B', but is a better grade than 'C'.

To be minus something means not to have that thing.

A minus is a disadvantage.

You use plus or minus to give the amount by which a particular number may vary.