First of all I started with working out which pairs of numbers would go into it.
7=3+4,5+2,7+0 and 6+1
8=7+1,6+2,5+3 and 8+0
13=6+7,9+4 and 8+5
14=9+5 and 6+8
3=1+2 and 3+0
Then I looked at the stament saying: Find out the pairs in box 8.
So I looked at my pairs and thought maybe 5+3. So I wrot that down on my whiteboard.
Then I looked at box nunber 7. Thinking that it could be 3+4 but it couldn't be possible because box 8 was 5+3 and you can't use the same number twice. So I thought it could be 7+0.
I then moved onto box 13. I looked at the possible answers. 9+4 looked fine so I chose it.
I then worked out which numbers I had left. 6,2,1 and 8.
So I moved onto box 14. Only two of the numbers fitted into 14. 6+8. So I wrote down 6 and leaving me with 1 and which goes into 3!
Box 7= 7+0
Box 8= 5+3
Box 13= 9+4
Box 14+ 6+8
Box 3= 1+2
That's How I worked out this problem!
:)