题目内容
计算(能简算的要简算).
(15+)× | -× | 13×+×15 |
87× | ××32 | +×. |
解:(1)(15+)×,
=15×+×,
=2+,
=2;
(2)-×,
=(1-),
=,
=;
(3)13×+×15,
=×(13+15),
=28,
=6;
(4)87×,
=86×+1×,
=3,
=3;
(5)××32,
=(4)×(8),
=5×1,
=5;
(6)+×,
=,
=3.
分析:(1)(2)(3)(4)运用乘法分配律解答,
(5)化32=4×8,再运用乘法交换律和结合律解答,
(6)按照先算乘法再算加法顺序解答.
点评:本题考查知识点:(1)简便算法正确运用,(2)四则计算准确性.
=15×+×,
=2+,
=2;
(2)-×,
=(1-),
=,
=;
(3)13×+×15,
=×(13+15),
=28,
=6;
(4)87×,
=86×+1×,
=3,
=3;
(5)××32,
=(4)×(8),
=5×1,
=5;
(6)+×,
=,
=3.
分析:(1)(2)(3)(4)运用乘法分配律解答,
(5)化32=4×8,再运用乘法交换律和结合律解答,
(6)按照先算乘法再算加法顺序解答.
点评:本题考查知识点:(1)简便算法正确运用,(2)四则计算准确性.
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