递等式计算,写出必要的计算过程,能简便计算的用简便方法计算:
1个回答

解题思路:(1)、(5)、(6)、(7)、(8)按照有括号的先算括号里面的,没有括号时先算乘除法,后算加减法的顺序计算;

(2)、(3)运用乘法分配律进行简算得解;

(4)运用乘法结合律简算得解.

(1)7.06×2.4-5.7,

=16.944-5.7,

=11.244;

(2)5.4×99+5.4,

=5.4×(99+1),

=5.4×100,

=540;

(3)9.6×72+9.6×28,

=9.6×(72+28),

=9.6×100,

=960;

(4)(1.25×2.5)×4,

=1.25×(2.5×4),

=1.25×10,

=12.5;

(5)10.4+72×0.81,

=10.4+58.32,

=68.72;

(6)11×0.6×0.4,

=6.6×0.4,

=2.64;

(7)(12.8+4.99)÷0.2,

=17.79÷0.2,

=88.95;

(8)1.25×8+2.5×4.4,

=10+2.5×0.4×11,

=10+11,

=21.

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: 此题考查小数四则混合运算与简便计算,完成本题要注意分析式中数据,运用合适的简便方法计算.