0.64×25×7.8+2.2
2÷2.5+2.5÷2
194－64.8÷1.8×0.9
36.72÷4.25×9.9
5180－705×6
24÷2.4－2.5×0.8
(4121+2389)÷7
671×15-974
469×12+1492
405×(3213-3189)
1.0.64×25×7.8+2.2
2.2÷2.5+2.5÷2
3.194－64.8÷1.8×0.9
4.36.72÷4.25×9.9
5.5180－705×6
6.24÷2.4－2.5×0.8
7.(4121+2389)÷7
8.671×15-974
9.469×12+1492
10.405×(3213-3189)
11.(25%-695%-12%)*36
12. 3/4*3/5+3/4*2/5
13. (1-1/4+8/9)/7/9
14 2/3+1/6/3/24+2/21
15 1*8/15*3/5
16 10-3/4/9/10-1/6
17 [(1/3+1/2)/5/6-1/3]/1/7
18 2/3/5+3/5/2+3/4
19 1/[(2-2/3/1/2)]*2/5