题目内容
脱式计算.(能简算的要简算)
0.125×0.25×8×4 | 6.6×12+8×6.6 |
[5-1.7÷(2-1)]×1 | 20×2.5÷(10×0.7+3) |
分析:(1)根据乘法交换律和结合律进行简算;
(2)根据乘法分配律进行简算;
(3)先算小括号里面的减法,再算中括号里面的除法,再算中括号里面的减法,最后算乘法;
(4)先算小括号里面的乘法,再算小括号里面的加法,最后按照从左向右的顺序进行计算.
(2)根据乘法分配律进行简算;
(3)先算小括号里面的减法,再算中括号里面的除法,再算中括号里面的减法,最后算乘法;
(4)先算小括号里面的乘法,再算小括号里面的加法,最后按照从左向右的顺序进行计算.
解答:解:
(1)0.125×0.25×8×4,
=(0.125×8)×(0.25×4),
=1×1,
=1;
(2)6.6×12+8×6.6,
=6.6×(12+8),
=6.6×20,
=132;
(3)[5-1.7÷(2-1)]×1,
=[5-1.7÷1]×1,
=[5-1.7]×1,
=3.3×1,
=3.3;
(4)20×2.5÷(10×0.7+3),
=20×2.5÷(7+3),
=20×2.5÷10,
=50÷10,
=5.
(1)0.125×0.25×8×4,
=(0.125×8)×(0.25×4),
=1×1,
=1;
(2)6.6×12+8×6.6,
=6.6×(12+8),
=6.6×20,
=132;
(3)[5-1.7÷(2-1)]×1,
=[5-1.7÷1]×1,
=[5-1.7]×1,
=3.3×1,
=3.3;
(4)20×2.5÷(10×0.7+3),
=20×2.5÷(7+3),
=20×2.5÷10,
=50÷10,
=5.
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.
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