题目内容
怎样简便就怎样算.
5.5×17.3+2.7×5.5 | 1.25×(6.2-5.9)×80 | 1.05×99 |
70.3-17.48÷7.6 | 3.64÷52×23.3 | 4.6×(1-0.25)+0.75×5.4 |
考点:小数四则混合运算,运算定律与简便运算
专题:运算顺序及法则
分析:(1)运用乘法分配律进行简算;
(2)先算减法,再根据乘法交换律进行简算;
(3)根据乘法分配律进行简算;
(4)先算除法,再算减法;
(5)按照从左到右的顺序计算;
(6)先算小括号里面的减法,然后再根据乘法分配律进行简算.
(2)先算减法,再根据乘法交换律进行简算;
(3)根据乘法分配律进行简算;
(4)先算除法,再算减法;
(5)按照从左到右的顺序计算;
(6)先算小括号里面的减法,然后再根据乘法分配律进行简算.
解答:
解:(1)5.5×17.3+2.7×5.5
=5.5×(17.3+2.7)
=5.5×20
=110;
(2)1.25×(6.2-5.9)×80
=1.25×0.3×80
=1.25×80×0.3
=100×0.3
=30;
(3)1.05×99
=1.05×(100-1)
=1.05×100-1.05×1
=105-1.05
=103.95;
(4)70.3-17.48÷7.6
=70.3-2.3
=68;
(5)3.64÷52×23.3
=0.07×23.3
=1.631;
(6)4.6×(1-0.25)+0.75×5.4
=4.6×0.75+0.75×5.4
=(4.6+5.4)×0.75
=10×0.75
=7.5.
=5.5×(17.3+2.7)
=5.5×20
=110;
(2)1.25×(6.2-5.9)×80
=1.25×0.3×80
=1.25×80×0.3
=100×0.3
=30;
(3)1.05×99
=1.05×(100-1)
=1.05×100-1.05×1
=105-1.05
=103.95;
(4)70.3-17.48÷7.6
=70.3-2.3
=68;
(5)3.64÷52×23.3
=0.07×23.3
=1.631;
(6)4.6×(1-0.25)+0.75×5.4
=4.6×0.75+0.75×5.4
=(4.6+5.4)×0.75
=10×0.75
=7.5.
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.
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