题目内容
计算下面各题,能简算的要简算
7.65-0.65×6 | 9.43-1.68-4.32 | 1.25×0.76×0.8 |
0.32×7.5-0.32×4.5 | 3.8×10.1 | 9.9÷[16.5-(1.7+3.8)]. |
分析:(1)先算乘法,再算减法;
(2)运用减法的性质简算;
(3)运用乘法交换律与结合律简算;
(4)运用乘法分配律简算;
(5)把10.1看作10+0.1,运用分配律简算;
(6)先算小括号内的,再算中括号内的,最后算括号外的.
(2)运用减法的性质简算;
(3)运用乘法交换律与结合律简算;
(4)运用乘法分配律简算;
(5)把10.1看作10+0.1,运用分配律简算;
(6)先算小括号内的,再算中括号内的,最后算括号外的.
解答:解:(1)7.65-0.65×6,
=7.65-3.9,
=3.75;
(2)9.43-1.68-4.32,
=9.43-(1.68+4.32),
=9.43-6,
=3.43;
(3)1.25×0.76×0.8,
=(1.25×0.8)×0.76,
=1×0.76,
=0.76;
(4)0.32×7.5-0.32×4.5,
=0.32×(7.5-4.5),
=0.32×3,
=0.96;
(5)3.8×10.1,
=3.8×(10+0.1),
=38+0.38,
=38.38;
(6)9.9÷[16.5-(1.7+3.8)],
=9.9÷[16.5-5.5],
=9.9÷11,
=0.9.
=7.65-3.9,
=3.75;
(2)9.43-1.68-4.32,
=9.43-(1.68+4.32),
=9.43-6,
=3.43;
(3)1.25×0.76×0.8,
=(1.25×0.8)×0.76,
=1×0.76,
=0.76;
(4)0.32×7.5-0.32×4.5,
=0.32×(7.5-4.5),
=0.32×3,
=0.96;
(5)3.8×10.1,
=3.8×(10+0.1),
=38+0.38,
=38.38;
(6)9.9÷[16.5-(1.7+3.8)],
=9.9÷[16.5-5.5],
=9.9÷11,
=0.9.
点评:此题考查了小数的四则混合运算,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.
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