Respuesta :

Add the numbers, then divide your new number by how many original numbers there are. 7 + 9 = 16, then 16 / 2 = 8, so your mean is 8.
There are many ways of doing this:

1. Add 7+9=16/2=8

2. (Personal Invented Method) look at a number line 

1-2-3-4-5-6-7-8-9-10
now look at 7 and nine what is in the middle?
8

Hopes This Helps:)