a) 64-5=59
59x2=177
52+177=229
b)63:9=7
100-7=93
3x93=279
310-279=31
c)30x2=61
61:10=6
120:6=20
64-20=44
44-4=40
d)99+3=102
102x21=2142
2142x0=0
0:8=0
e)104:2+(6+36:6)×5
36:6=6
6+6=12
12x5=60
104:2=52
52+60=112
f)3+3×(3+3×3)-36:9:2
3x3=9
9+3=12
12x3=36
36+3=39
39-36:9:2=
36:9=4
4:2=2
39+2=41