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精诚教育小学奥数举一反三练习题

发布时间:2013-12-28 10:41:32  

小学奥数举一反三练习题

一、 加减巧算(凑整法)

(1)199+74= (2)347+102=

(3)784—297= (4)1384—501=

(5)83+78+80+77+84+79 (6)9999+999+99+9= = =

= =

= =

= =

(6)487+321+113+479 (7)723—251—177 = =

= =

= =

(8)321+(279—155) (9)372—(54+72) = =

= =

= =

(10)1000—81—19—82—18—83—17—84—16

=

=

=

二、乘法速算

(1)12×11= (2)23×11= (3)45×11=

(4)87×11= (5)135×11= (6) 603×11=

一个数乘以15,等于这个数加上它的一半再乘以10:

(7)32×15 (8)438×15 (9)8762×15 = = = = = = = = =

一个数乘以25要想到25×4=100

(10)32×25 (11)81×25 (12)473×25 = = =

(13)52×9 (14)72×99 (15)1564×9 = = = = = =

“用头同尾合十”乘法

(16)18×12= 301×309=

二、 乘除巧算

交换位置,简便运算

(1)25×23×4=

(3)5×25×2×4=

拆分法,快速运算

(5)125×32

=

=

(7)25×12

=

=

(9)72×101

=

=

=

运用“商不变”性质

(11)170÷5

=

=

乘法分配律

(14)26×49 +49×74

=

=

= (2)125×27×8= (4)2×125×8×5= (6)125×16×5 = = (8)25×8×5 = = (10)21×201 = = = 12)7200÷25 (13)32000÷125 = = = = (15)68×99+68 = = = (

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