Ok, I'm putting myself up here for anonymous public humiliation but I still don't get it ...
The numbers 1 to 9 add up to ....
Do you mean:
1+2+3+4+5+6+7+8+9 = 45
Why do we need to add all those together?
However 1 , 4 and 2 appear in two rows so we need to add on 7 which gives us ....
I can see that 1+4+2=7 but do not understand why we need to 'add on7'.
The total divided by 4 is ....
I can see that there are 4 rows, so 52 ./. 4 =13
So if we subtract 1 and 4 we know the missing number is ....
And then I can put all the numbers in. So the missing answer requested is '8' (if I've done the above correctly); then, inbetween the 4 and 2 is '7' (because all lines have to add up to 13) and I then worked out that the line beginning with 2 would have to have '6' and '5' in it to add to 13 and the line ending with 1 would have to have '9' and '3' in it to add up to 13. And then I've used all the numbers. So I can see that it does work, but I don't know why you have to do the adding 1-9 bit and then adding on '7' (from the numbers already given). What am I doing when I do those two things?
Sorry, I know it's me. I can't even blame sleepless nights up with babies and too much wine and age because I couldn't do this sort of thing when I was lying in, going to the gym and 21!