1. You can find 5 + 8 by simply adding the two numbers together.
2. Or, you can use family factors 6 + 7, 4 + 9, 3 + 10 etc...
3. You can break down each term and add smaller numbers still equivalent to the original term (5 = 3+2 and 8 = 4+4, so you can add 3+2+4+4 to get the same answer)