289-46-64                   298+102                   45×18
420÷35                     154+36+46                 810÷45÷3.
分析:(1)根據(jù)減法的性質(zhì)簡算;
(2)運(yùn)用湊整法簡算;
(3)根據(jù)積不變規(guī)律,第一個(gè)因數(shù)乘上2,第二個(gè)因數(shù)除以2;
(4)根據(jù)商不變規(guī)律,把被除數(shù)和除法先同時(shí)除以7,再計(jì)算;
(5)運(yùn)用加法交換律簡算;
(6)按照從左到右的順序計(jì)算.
解答:解:(1)289-46-64,
=289-(46+64),
=289-110,
=179;

(2)298+102,
=(300-2)+(100+2),
=(300+100)+(2-2),
=400+0,
=0;

(3)45×18,
=(45×2)×(18÷2),
=90×9,
=810;

(4)420÷35,
=(420÷7)÷(35÷7),
=60÷5,
=12;

(5)154+36+46,
=(154+46)+36,
=200+36,
=236;

(6)810÷45÷3,
=18÷3,
=6.
點(diǎn)評:完成本題要注意分析式中數(shù)據(jù),運(yùn)用合適的簡便方法計(jì)算.
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289-46-64         298+102         45×18
420÷35          154+36+46        810÷45÷3.

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