题目内容
利用加法交换律和结合律,将相加得整百、整千的数先相加,再算出结果.
136+146+354=
706+236+194=
319+171+229=
1306+1064+336=
1266+1304+334=
738+388+162=
136+146+354=
706+236+194=
319+171+229=
1306+1064+336=
1266+1304+334=
738+388+162=
分析:(1)根据加法结合律进行简算;
(2)根据加法交换律进行简算;
(3)根据加法结合律进行简算;
(4)根据加法结合律进行简算;
(5)根据加法交换律进行简算;
(6)根据加法交换律进行简算.
(2)根据加法交换律进行简算;
(3)根据加法结合律进行简算;
(4)根据加法结合律进行简算;
(5)根据加法交换律进行简算;
(6)根据加法交换律进行简算.
解答:解:(1)136+146+354
=136+(354+146)
=136+500
=636;
(2)706+236+194
=706+194+236
=900+236
=1136;
(3)319+171+229
=319+(171+229)
=319+400
=719;
(4)1306+1064+336
=1306+(1064+336)
=1306+1400
=1706;
(5)1266+1304+334
=1266+334+1304
=1600+1304
=2904;
(6)738+388+162
=738+162+388
=900+388
=1288.
=136+(354+146)
=136+500
=636;
(2)706+236+194
=706+194+236
=900+236
=1136;
(3)319+171+229
=319+(171+229)
=319+400
=719;
(4)1306+1064+336
=1306+(1064+336)
=1306+1400
=1706;
(5)1266+1304+334
=1266+334+1304
=1600+1304
=2904;
(6)738+388+162
=738+162+388
=900+388
=1288.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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