There are 6 ways we can subtract from 5:
5 - 0 = 5
5 - 1 = 4
5 - 2 = 3
5 - 3 = 2
5 - 4 = 1
5 - 5 = 0
Great job! Now, try the practice to see if you got it. You'll have them memorized once you're done.