Distributive property of division is that the division of a sum equals the division of the summands.
Algebraically, this is:
[x + y + z] / a = x/a + y/a + z/a.
So, applying this to 144 / 8, you can split 144 as [72 + 32 + 40] / 8 = 72/8 + 32/8 + 40/8 = 9 + 4 + 5 = 18