简算.1.25×0.72

1个回答

  • 解题思路:(1)首先把0.72分成0.8×0.9,然后根据乘法结合律简算即可;

    (2)根据加法交换律和加法结合律简算即可;

    (3)根据乘法分配律简算即可;

    (4)根据乘法分配律简算即可;

    (5)根据乘法分配律简算即可;

    (6)根据乘法分配律简算即可.

    (1)1.25×0.72

    =1.25×0.8×0.9

    =0.9

    (2)50.27+5.6-10.27

    =50.27-10.27+5.6

    =40+5.6

    =45.6

    (3)5.65×9.9+0.565

    =5.65×9.9+5.65×0.1

    =5.65×(9.9+0.1)

    =5.65×10

    =56.5

    (4)(0.4+40)×2.5

    =0.4×2.5+40×2.5

    =1+100

    =101

    (5)10.1×101-10.1

    =10.1×(101-1)

    =10.1×100

    =1010

    (6)9.7×0.72-0.7×0.72+0.72

    =0.72×(9.7-0.7+1)

    =0.72×10

    =7.2

    点评:

    本题考点: 运算定律与简便运算;小数四则混合运算.

    考点点评: 此题主要考查了加法、乘法运算定律在简算中的应用.