300道脱式计算及答案

（1）2.5*32*0.125

=（2.5*4）*（8*0.125）

=10*1

=10

（2）3.5-7+6.5

=3.5+6.5-7

=3

（3）1.2×2.5+0.8×2.5

=2.5(1.2+0.8)

=25

（4）8.9×1.25-0.9×1.25

=1.25(8.9-0.9)

=10

（5）12.5×7.4×0.8

=12.5×0.8×7.4

=74

（6）6.5×9.5+6.5×0.5

=6.5×（9.5+0.5）

=6.5×10

=65

（7）0.35×1.6+0.35×3.4

=0.35*（1.6+3.4）

=0.35*5

=1.75

（8）6.72-3.28-1.72

=6.75-（3.28+1.72）

=6.75-5

=1.75

（9）0.45+6.37+4.55

=0.45+4.55+6.37

=5+6.37

=11.37

（10）28×12.5-12.5×20

=（28-20）*12.5

=8*12.5

=100

（11）23.65-（3.07+3.65）

=23.65-3.65-3.07

=20-3.07

=16.93

（12）（4+0.4×0.25）8×7×1.25

=（4+1）*7*10

=5*7*10

=350

（13）1.65×99+1.65

=1.65*（99+1）

=1.65*100

=165

（14）27.85-（7.85+3.4）

=27.85-7.85+3.4

=20+3.4

=23.4

（15）48×1.25+50×1.25×0.2×8

7.8×9.9+0.78

=7.8*（9.9+0.1）

=7.8*10

=78

（16）4.8×46+4.8×54

=（46+54）*4.8

=100*4.8

=480

（17）673-327-173

=673-（327+173）

=673-500

=173

（18）4.44*2.5

=1.11*（4*2.5）

=1.11*10

=11.1

（19）3.5÷1.4

=（3.5÷0.7）÷（1.4÷0.7）

=5÷2

=2.5

（20）1+2+3+4+5……+99+100

=（1+99）+（2+98）+（3+97）+.+（49+51）+50

=（100÷2-1）*100+50

=4900+50

=4950

62×7.1+2.9,

=440.2+2.9,

=443.1；

4.2×0.25,

=（4+0.2）×0.25,

=4×0.25+0.2×0.25,

=1+0.05,

=1.05；

5.2×4.3+0.8×4.3,

=（5.2+0.8）×4.3,

=6×4.3,

=25.8．

8.5+1.5÷0.25×4,

=8.5+6×4,

=8.5+24,

=32.5．

0.25×0.8+2.5% 

=0.2+2.5%,

=0.225；

32×125×2.5,

=4×8×125×2.5,

=8×125×（4×2.5）,

=1000×10,

=10000；

94÷（6.84×8.5-31.46÷0.55）,

=94÷（58.14-57.2）,

=94÷0.94,

=100．

13÷0.4÷2.5,

=13÷（0.4×2.5）,

=13÷1,

=13；

1.25×2.5×0.8,

=（1.25×0.8）×2.5,

=1×2.5,

=2.5；

1.5×101-1.5,

=1.5×（101-1）,

=1.5×100,

=150；

4.8×101,

=4.8×100+4.8×1,

=480+4.8,

=484.8．

3.25×4.7-7.8,

=15.275-7.8,

=7.475；

0.57+0.43×0.24,

=0.57+0.1032,

=0.6732．

945÷5÷3,

=189÷3,

=63；

152×3÷2,

=456÷2,

=228；

43×12×6,

=516×6,

=3096．

200+25×33,

=200+825,

=1025；

（25+26）×48,

=51×48,

=2448．

576-（290+107）,

=576-397,

=179；

649+124-556,

=773-556,

=217．

4.82-5.2÷0.8×0.6,

=4.82-6.5×0.6,

=4.82-3.9,

=0.92．