1. 34-78= 34000-78=33922
2.45-12=450-12=438
3.1-1200=1000000-1200=998800
4.221-120=2210-120=2090
5.5-26=5000-26=4974
6116-34=1160000-34=1159966
7.32-61=32000-61=3139
8.41-41=4100-41=4050
9.78-789=7800-789=7001
10.23-7600=23000-7600=15400
11.769-670=7690-670=7020
12. 4531+78643=453100+78643=531743