Question

五年级数学题（急急急~~~~~~~~）

用简便方法计算：
(1)12.5X3.2X2.5
(2)62.7-62.7X0.99
(3)7.6X7.6-7.6X1.4+7.6X3.8

Answer 1

12.5X3.2X2.5
=12.5*8*0.4*2.5=10*1=10

62.7*`1-62.7*0.99=62.7*0.01=0.627

7.6X7.6-7.6X1.4+7.6X3.8=7.6*(7.6-1.4+3.8)=7.6*10=76

Answer 2

(1)12.5X3.2X2.5
=12.5*8*0.4*2.5
=100*1
=100
(2)62.7-62.7X0.99
=62.7*(1-0.99)
=62.7*0.01
=0.627
(3)7.6X7.6-7.6X1.4+7.6X3.8
=7.6*(7.6-1.4+3.8)
=7.6*10
=76

Answer 3

（1） 12.5* 3.2* 2.5=12.5* (8* 0.4)* 2.5=12.5* 8* 0.4*2.5=100
（2） 62.7-62.7* 0.99=62.7*（1-0.99）=0.627
（3） 7.6* 7.6-7.6* 1.4+7.6* 3.8=7.6*（7.6-1.4+3.8）=76

Answer 4

1:12.5X3.2X2.5
=12.5*(3+0.2)*2.5
=(12.5*0.2+12.5*3)*2.5
=40*2.5
=100

2:62.7-62.7X0.99
=62.7*(1-0.99)
=62.7*0.01
=0.627

3:7.6X7.6-7.6X1.4+7.6X3.8
=7.6*(7.6-1.4+3.8)
=7.6*10
=76

Answer 5

(1)=12.5×（8×4）×2.5
=(12.5×8)×（4×2.5）
=100×10
=1000
（2）=62.7×1.00-62.7×0.99
=62.7×（1-0.99）
=62.7×0.01
=0.627
（3）=7.6×（7.6-1.4+3.8）
=7.6×10
=76