计算下列各题.(能简算的要简算).

1个回答

  • 解题思路:(1)按运算顺序从左往右依次运算;(2)运用乘法分配律简算;(3)先算括号内的乘法,再算括号内的加法,最后算括号外的除法;(4)先算除法,再算加法;(5)把原式变为0.74+9×0.74,运用乘法分配律简算;(6)运用除法的性质简算.

    (1)91÷2.6÷0.05,

    =35÷0.05,

    =700;

    (2)6.3×3.7+6.3×6.3,

    =6.3×(3.7+6.3),

    =6.3×10,

    =63;

    (3)(3.7+1.7×0.4)÷2.5,

    =(3.7+0.68)÷2.5,

    =4.38÷2.5,

    =1.752;

    (4)7.28+3.2÷2.5,

    =7.28+1.28,

    =8.56;

    (5)0.74+0.9×7.4,

    =(1+9)×0.74,

    =10×0.74,

    =7.4;

    (6)7.8÷0.125÷0.8,

    =7.8÷(0.125×0.8),

    =7.8÷0.1,

    =78.

    点评:

    本题考点: 小数四则混合运算;运算定律与简便运算.

    考点点评: 此题考查了小数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.