You can both compare and order integers by subtracting them:
If the difference is zero, as the name suggests...there's no difference! So, the integers are the same. For example, you have
If the difference is positive, then the first integer is bigger than the second. For example: and we deduce that 5 is greater than 2, 18 is greater than -2 and -3 is greater than -10
If the difference is negative, then the first integer is less than the first. For example, if we invert the previous differences, we have and we deduce that 2 is less than 5, -2 is less than 18 and than -10 is less than -3