Your program had the message, but the console actually responded and it ran.
this program is just supposed to take values that I stored in memory and add them. I think i am doing it right.
.data
A: .word 7
B: .word 5
Sum: .word 0
Dif: .word 0
.text
.gobl main
main:
la $s1, A
la $s2, B
la $s3, Sum
la $s4, Dif
add $s3, $s1, $s2
sub $s4, $s1, $s2