Addition and subtraction : 
1 + 1 = 2
2 - 1 = 1

Multiplication, division, and modulus :
5 % 2 = 1
5 % 0 = $rem2
7 % 2 = 1
5 / 2 = 2
5 / 0 = $rem4
5 * 2 = 10

5 * -1 = -5
5 * -2 = -10
5 * -2 = -10

And now null nodes to make sure it doesn't throw an NPE :