简便计算 14.35+3.98+2.65 12.5-8.14-1.86 23.1-(12.1-2.46 ) 1

1个回答

  • 解题思路:(1)根据加法交换律和结合律简便计算;

    (2)根据连减的简便方法计算即可;

    (3)先去括号,再从左往右计算;

    (4)先变形为125×8×7,再进行计算;

    (5)(6)根据乘法分配律简便计算.

    (1)14.35+3.98+2.65

    =14.35+2.65+3.98

    =17+3.98

    =20.98;

    (2)12.5-8.14-1.86

    =12.5-(8.14+1.86)

    =12.5-10

    =2.5;

    (3)23.1-(12.1-2.46 )

    =23.1-12.1+2.46

    =11+2.46

    =13.46;

    (4)125×56

    =125×8×7

    =1000×7

    =7000;

    (5)56×75+44×75

    =(56+44)×75

    =100×75

    =7500;

    (6)101×43-43

    =(101-1)×43

    =100×43

    =4300.

    点评:

    本题考点: 运算定律与简便运算.

    考点点评: 考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.