计算下面各题(能简算的要简算) (1)89+124+11+26+48 (2)(64-224÷14)×12 (3)120×

1个回答

  • 解题思路:(1)利用加法交换律与结合律简算;

    (2)(3)先算除法,再算减法,最后算乘法;

    (4)利用乘法分配律简算;

    (5)乘法利用结合律简算,最后算加法;

    (6)利用交换律先算减法,再算乘法;

    (7)把99=100-1,利用乘法分配律简算;

    (8)把64=8×8简算.

    (1)89+124+11+26+48

    =(89+11)+(124+26+48)

    =100+198

    =298;

    (2)(64-224÷14)×12

    =(64-16)×12

    =48×12

    =576;

    (3)120×(38+405÷27)

    =120×(38+15)

    =120×53

    =6360;

    (4)163×25+237×25

    =(163+237)×25

    =400×25

    =10000;

    (5)384+98×25×4

    =384+98×(25×4)

    =384+98×100

    =384+9800

    =10184;

    (6)724+26×24-724

    =724-724+26×24

    =26×24

    =26×4×6

    =104×6

    =624;

    (7)365×99

    =365×(100-1)

    =365×100-365×1

    =36500-365

    =36135;

    (8)125×64

    =125×8×8

    =1000×8

    =8000.

    点评:

    本题考点: 整数四则混合运算;运算定律与简便运算.

    考点点评: 整数混合运算的关键是抓住运算顺序,正确利用运算定律简算.