マイナス

まいなす
noun, na-adjective
minus; negative
number
1. minus; subtraction
The mathematical operation of subtracting, or the minus sign (−).
10マイナス37です
Ten minus three is seven.
100マイナス5050です
One hundred minus fifty is fifty.
I put a minus sign in the calculation.
2. negative; disadvantage
A negative aspect or detrimental factor.
それマイナスなる
That will be a disadvantage.
それマイナスなる
That will be a disadvantage.
There are negative aspects, but there are positive aspects too.
This news is bad for the company's image.
3. below zero
Temperatures below zero degrees.
The temperature dropped to minus 5 degrees.
マイナス20()(さむ)すぎる
Minus 20 degrees is too cold.
When the temperature drops to minus ten degrees, the water pipes may freeze.

マイナス is used for mathematical subtraction and figuratively for negative aspects.

Math usage

Negative meaning

Temperature usage

The opposite is プラス (plus/positive).