when you add secretly a one
23
They are: 2+3 = 5
3+2=5, so there you go!!
31
Both numbers add up to 7
The prime numbers of 20 are 2, 2 and 5. (2*2*5 = 20)
it is 61 + 2 + 3 because if you add 61 + 5 it = 66 so if you split 5 into 2 and 3 it = 5 then add 61 to 5 and you get 66
8 and 5
5 and 23
5+13
16
-13