脱式计算(能简便的要简便).8.8×12.5×0.70.64×0.25×1.25×506.42×13.51+13.51×
2个回答

解题思路:(1)把8.8化成1.1×8,再运用乘法的交换律、结合律进行简算;

(2)把0.64化成0.8×0.8,再运用乘法的交换律、结合律进行简算;

(3)运用乘法的分配律进行简算;

(4)运用乘法的分配律进行简算;

(5)先算乘法,再算减法;

(6)先算乘法,再算加法;

(7)先算小括号里的减法,再算括号外的乘法;

(8)先求出乘法算式的积,再算减法;

(9)运用乘法的分配律进行简算;

(10)运用乘法的分配律进行简算.

(1)8.8×12.5×0.7

=1.1×8×12.5×0.7

=(1.1×0.7)×(8×12.5)

=0.77×100

=77;

(2)0.64×0.25×1.25×50

=0.8×0.8×0.25×1.25×50

=(0.8×1.25)×(0.8×0.25×50)

=1×10

=10;

(3)6.42×13.51+13.51×3.58

=(6.42+3.58)×13.51

=10×13.51

=135.1;

(4)6.75×87.12-77.12×6.75

=(87.12-77.12)×6.75

=10×6.75

=67.5;

(5)16-3.12×1.5

=16-4.68

=11.32;

(6)12.8+7.2×0.3

=12.8+2.16

=14.96;

(7)8.15×(12.75-8.95)

=8.15×3.8

=30.97;

(8)5.62×3.1-2.1×1.38

=17.422-2.898

=14.524;

(9)5.23×0.76+52.3×0.024

=5.23×0.76+5.23×0.24

=5.23×(0.76+0.24)

=5.23×1

=5.23;

(10)96.51×3.1+3.1×4.59-3.1

=(96.51+4.59-1)×3.1

=100.1×3.1

=(100+0.1)×3.1

=100×3.1+0.1×3.1

=310+0.31

=310.31.

点评:

本题考点: A:运算定律与简便运算 B:小数四则混合运算

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律简便计算.