Hi music lover,
I am a little confused as to whether this is 1 problem or 4 different problems but I will take a look.
1) AYE+AYE+AYE=EASY
2) SON+ON+MOON=SOON
3) EAT+MA+EAT=MEAT
4) NO+GUN+NO=HUNT
I will look at the first one
Line them up under each other - that will help you thinkg better.
1) 3* AYE=easy
If a number is divisable by 3 then the sum of the digits must be digits must be divisable by three - that might help later.
2) 3E = 0,3,6,9,12,15,18,21,24 or 27 that doesn't help a whole lot yet..... except that only 0,1 or 2 can be carried to the tens column.
3) A must be 3 or bigger than 3 or else there will not be any cary for the the first e in easy. A>2
4) If you add any 3 single digit numbers plus a carry the biggest number you can get is 4*9=36 so there can never be more than 3 carried to the next column.
This means that E must be 1,2 or 3 (this is the most helpful clue that I stubled upon)
If E=1 then
531
531
531
-------
1593
-------
That works !!! 
I don't think any other combinations work :// But you should check E=2 and E=3 combinations.
All I have done here is given you an idea of the thought processes needed.
If you are a good maths student exercises like this are fun but they also really help you get a fuller understanding of how numbers work together,
You should try the others yourself :)
