题目内容
怎样简便怎样算: 125×23×8 |
46×64+64×54 |
(567-462)×24 | 15×27×16 |
6.25+3.52-0.65 | 16.8+36.7+33.2. |
分析:(1)根据乘法交换律简算;
(2)运用乘法分配律简算;
(3)先算小括号里面减法,再运用乘法分配律简算;
(4)先把16分解4×4,再根据乘法结合律简算;
(5)按照从左到右的顺序计算;
(6)根据加法交换律简算.
(2)运用乘法分配律简算;
(3)先算小括号里面减法,再运用乘法分配律简算;
(4)先把16分解4×4,再根据乘法结合律简算;
(5)按照从左到右的顺序计算;
(6)根据加法交换律简算.
解答:解:(1)125×23×8
=125×8×23
=1000×23
=23000;
(2)46×64+64×54
=64×(46+54)
=64×100
=6400;
(3)(567-462)×24
=105×24
=(100+5)×24
=100×24+5×24
=2400+120
=2520;
(4)15×27×16
=15×27×(4×4)
=(15×4)×(27×4)
=60×108
=6480;
(5)6.25+3.52-0.65
=9.77-0.65
=9.12;
(6)16.8+36.7+33.2
=16.8+33.2+35.7
=50+35.7
=85.7.
=125×8×23
=1000×23
=23000;
(2)46×64+64×54
=64×(46+54)
=64×100
=6400;
(3)(567-462)×24
=105×24
=(100+5)×24
=100×24+5×24
=2400+120
=2520;
(4)15×27×16
=15×27×(4×4)
=(15×4)×(27×4)
=60×108
=6480;
(5)6.25+3.52-0.65
=9.77-0.65
=9.12;
(6)16.8+36.7+33.2
=16.8+33.2+35.7
=50+35.7
=85.7.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
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