• 8 − 5
  • 1 + 0
  • 0 + 1
  • 1 + 1

This is a way to make 2:

  • 1 + 1 = 2

These are not ways to make 2:

  • 8 − 5 = 3
  • 1 + 0 = 1
  • 0 + 1 = 1
  • 3 + 4
  • 8 − 0
  • 6 + 2
  • 5 + 3

This is a way to make 7:

  • 3 + 4 = 7

These are not ways to make 7:

  • 8 − 0 = 8
  • 6 + 2 = 8
  • 5 + 3 = 8
  • 1 + 3
  • 0 + 2
  • 10 − 7
  • 6 − 0

This is a way to make 4:

  • 1 + 3 = 4

These are not ways to make 4:

  • 0 + 2 = 2
  • 10 − 7 = 3
  • 6 − 0 = 6