Prerequisites: Addition

Subtraction deals with the taking away of numbers, like number a from number b so that: a >= b while b > a. Such a case is with:

${\displaystyle 36-5=31}$.

a = 36 and b = 5.

So a - b = 36-５ = 31, a >= b is true.

a>=b, like ${\displaystyle 36-5=31}$.

But b>a, for example : ${\displaystyle 36-55=-19}$.

a = 36 and b = 55.

${\displaystyle a-b=36-55=-19}$.

Subtraction is the inverse of addition, meaning that it is the opposite.

${\displaystyle 31+5=36}$, ${\displaystyle 36-5=31}$