4th grade algebra
posted by Judy .
7  7  7  7 = ?
12  15  10  8 = ?
3  7  4  2 = ?
11  9  6  6 = ?
6  5  4  2 = ?
8  5  5  5 = ?
12  7  5  4 = ?
13  3  6  1 = ?
16  10  2  3 = ?
8  2  2  2 = ?
I am not understanding how to help figure these problems out? I would greatly appreciate the help so I can teach my son how to get these answers.

You're adding negative numbers. As you've typed the above, all of the first numbers are positive.
7  7  7  7 = 21
12  15  10  8 = 21
Can you do the rest?
This number line may help you.
http://www.mathsisfun.com/numberline.html 
1. 7 7  7 7,
First, Add all numbers with like signs:
7  21,
Subtract the smaller number from the
larger number and use the sign of the
larger number:
7  21 = 14.
2. 12  15  10  8,
12  33 =  21.
3. 3  7  4  2,
3  14 =  11.
All of the remaining problems are similar to the first three. So let's
try one that's a little different:
7 + 7 + 7 + 7 =
Add all numbers with like signs:
7 + 21,
Subtract the smaller number from the larger number and use the sign of the
larger number:
7 + 21 = 14.
6  5 + 8 + 10 =
11 + 18 = 7.
I hope this will help. 
CORRECTION:
3. 3  7  4  2 =
3  13 = 10.