题目内容
计算下面各题.(能简算的要简算) (1)(12.5×8-40)÷0.6 | (2)7.25×16.3-12.3×7.25 |
(3) | (4)91+91× |
(5)5.2×101 | (6)14.6-3.625-6.375. |
解:(1)(12.5×8-40)÷0.6,
=(100-40)÷0.6,
=60÷0.6,
=100;
(2)7.25×16.3-12.3×7.25,
=(16.3-12.3)×7.25,
=4×7.25,
=4×(7+0.25),
=28+1,
=29;
(3)(+)÷,
=×8,
=13;
(4)91+91×(-),
=91+91×-91×,
=91+14-13,
=92;
(5)5.2×101,
=5.2×(100+1),
=520+5.2,
=525.2;
(6)14.6-3.625-6.375,
=14.6-(3.625+6.375),
=14.6-10,
=4.6.
分析:(1)先算括号内的乘法,再算括号内的减法,最后算括号外的除法;
(2)运用乘法分配律简算;
(3)先算括号内的,再算括号外的;
(4)运用乘法分配律简算;
(5)把101看作100+1,运用乘法分配律简算;
(6)运用减法的性质简算.
点评:此题考查了四则混合运算,注意运算顺序和运算法则,灵活运用定律或性质进行简算.
=(100-40)÷0.6,
=60÷0.6,
=100;
(2)7.25×16.3-12.3×7.25,
=(16.3-12.3)×7.25,
=4×7.25,
=4×(7+0.25),
=28+1,
=29;
(3)(+)÷,
=×8,
=13;
(4)91+91×(-),
=91+91×-91×,
=91+14-13,
=92;
(5)5.2×101,
=5.2×(100+1),
=520+5.2,
=525.2;
(6)14.6-3.625-6.375,
=14.6-(3.625+6.375),
=14.6-10,
=4.6.
分析:(1)先算括号内的乘法,再算括号内的减法,最后算括号外的除法;
(2)运用乘法分配律简算;
(3)先算括号内的,再算括号外的;
(4)运用乘法分配律简算;
(5)把101看作100+1,运用乘法分配律简算;
(6)运用减法的性质简算.
点评:此题考查了四则混合运算,注意运算顺序和运算法则,灵活运用定律或性质进行简算.
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