三年级数学思维训练:计算下面各题
用简便方法计算下面各题
①17100 ②11125 ③239
④2399 ⑤1234511 ⑥5678911
⑦3615 ⑧123254 ⑨456212525548
⑩2532125 (11)360025
答 案:①17100=1700 ②11125=5560 ③239=230-23=207 ④2399=2300-23=2277
⑤1234511=135795 ⑥5678911=624679⑦3615=(36+18)10=540
⑧123254=123(254)=12300⑨456212525548
=456(25)(254)(1258)
=456000000
⑩2532125
=(254)(1258)
=100000
(11)360025
=3610025
=364
=144
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