(1)79.76+84.7×0.2 (2)15.37+28.44+12.56 (3)(2.3×8.8-2.3×0.8)×
1个回答

解题思路:(1)先算乘法,再算加法;

(2)根据加法结合律进行计算;

(3)根据乘法分配律进行计算;

(4)先算除法,再算加法,再算减法,最后算乘法.

(1)79.76+84.7×0.2,

=79.76+16.94,

=96.7;

(2)15.37+28.44+12.56,

=15.37+(28.44+12.56),

=15.37+41,

=56.37;

(3)(2.3×8.8-2.3×0.8)×1.25,

=2.3×(8.8-0.8)×1.25,

=2.3×8×1.25,

=2.3×(8×1.25),

=2.3×10,

=23;

(4)[5.2-(2.5+7.5÷5)]×1.2,

=[5.2-(2.5+1.5)]×1.2,

=[5.2-4]×1.2,

=1.2×1.2,

=1.44.

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: 四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.