能简便的用简便方法计算.9.6+3.4×8.5÷2.89 3.28+6.
1个回答

解题思路:(1)先算乘法,再算除法,最后算加法;

(2)先算除法,再算加法;

(3)根据除法的性质进行简算;

(4)根据乘法分配律进行简算;

(5)先算加法和减法,再算乘法;

(6)先算括号里里面的加法,再算除法,最后算括号外面的加法.

(1)9.6+3.4×8.5÷2.89

=9.6+28.9÷2.89

=9.6+10

=19.6;

(2)3.28+6.72÷0.12

=3.28+56

=59.28;

(3)0.75÷0.25÷0.4

=0.75÷(0.25×0.4)

=0.75÷0.1

=7.5;

(4)5.78×4.25+5.78×5.75

=5.78×(4.25+5.75)

=5.78×10

=57.8;

(5)(0.9+1.11)×(10-0.8)

=2.01×9.2

=18.492;

(6)1.8+1.2÷(1.8+1.2)

=1.8+1.2÷3

=1.8+0.4

=2.2.

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: 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.