怎样简便就怎样算2.5×12.5×3.218.72-3.34-1.66-1.721.25×17.6+36÷0.8+2.6

1个回答

  • 解题思路:(1)首先把3.2分成8×0.4,然后根据乘法交换律和结合律简算即可;

    (2)根据加法交换律和减法的性质简算即可;

    (3)(4)(6)根据乘法分配律简算即可;

    (5)根据加法交换律和结合律简算即可.

    (1)2.5×12.5×3.2

    =2.5×12.5×8×0.4

    =(2.5×0.4)×(12.5×8)

    =1×100

    =100

    (2)18.72-3.34-1.66-1.72

    =18.72-1.72-(3.34+1.66)

    =17-5

    =12

    (3)1.25×17.6+36÷0.8+2.64×12.5

    =1.25×17.6+36×1.25+26.4×1.25

    =1.25×(17.6+36+26.4)

    =1.25×80

    =100

    (4)([5/8]+[1/27])×8+[19/27]

    =[5/8]×8+[1/27]×8+[19/27]

    =5+[1/27]×(8+19)

    =5+1

    =6

    (5)(+4.8)+(-14)+(-6)+(+15.2)

    =(4.8+15.2)-(14+6)

    =20-20

    =0

    (6)[567+345×566/567×345+222]

    =[567×345−345+567/567×345+222]

    =[567×345+222/567×345+222]

    =1

    点评:

    本题考点: 小数四则混合运算;运算定律与简便运算;分数的四则混合运算.

    考点点评: 此题主要考查了加法、乘法运算定律和减法的性质在简算中的应用.