1、 1小学奥数 找规律一、知识要点按照一定次序排列起来的一列数,叫做数列。如自然数列:1,2,3,4,双数列:2,4,6,8,我们研究数列,目的就是为了发现数列中数排列的规律,并依据这个规律来填写空缺的数。按照一定的顺序排列的一列数,只要从连续的几个数中找到规律,那么就可以知道其余所有的数。寻找数列的排列规律,除了从相邻两数的和、差考虑,有时还要从积、商考虑。善于发现数列的规律是填数的关键。 二、精讲精练【例题 1】在括号内填上合适的数。(1)3,6,9,12,( ),( )(2)1,2,4,7,11,( ),( )(3)2,6,18,54,( ),( )练习 1:在括号内填上合适的数。(1)2
2、,4,6,8,10,( ),( )(2)1,2,5,10,17,( ),( )(3)2,8,32,128,( ),( )(4)1,5,25,125,( ),( )(5)12,1,10,1,8,1,( ),( )【例题 2】先找出规律,再在括号里填上合适的数。(1)15,2,12,2,9,2,( ),( )(2)21,4,18,5,15,6,( ),( )2练习 2:按规律填数。(1)2,1,4,1,6,1,( ),( )(2)3,2,9,2,27,2,( ),( )(3)18,3,15,4,12,5,( ),( )(4)1,15,3,13,5,11,( ),( )(5)1,2,5,14,( )
3、,( )【例题 3】先找出规律,再在括号里填上合适的数。(1)2,5,14,41,( ) (2)252,124,60,28,( )(3)1,2,5,13,34,( ) (4)1,4,9,16,25,36,( )练习 3:按规律填数。(1)2,3,5,9,17,( ),( ) (2)2,4,10,28,82,( ),( )(3)94,46,22,10,( ),( ) (4)2,3,7,18,47,( ),( )【例题 4】根据前面图形里的数的排列规律,填入适当的数。(1) 5 109 147 1211 169 1413 (2) 94 37148 4281649 3 2712 4 3636 123
4、(3)练习 4:找出排列规律,在空缺处填上适当的数。(1)(3)【例题 5】按规律填数。(1)187,286,385,( ),( )(2)练习 5:根据规律,在空格内填数。(1)198,297,396,( ),( )(2)(3)3 75 98 1210 1412 16148 4 1616 8 3232 165 15 127 21 189 27(2) 4892768 28723 31254141 23464335 2432 54386421 45266532 5737 25389523 45277534 254三、课后作业1、仔细观察找出规律,再填数。(1)12,1,10,1,8,1,( ),(
5、 ),( )(2)3,5,10,12,17,( ),( ),( )(3)3,2,9,2,27,2,( ),( ),( )(4)1,2,2,4,3,8,4,16,5,( ),( ),( )(5)4,24,6,36,8,54,( ),( ),( )2、观察下面各数列的规律,然后在括号里填上适当的数。(1)1,0,2,5,3,10,4,15,( ),( ),( )(2)1,6,5,10,9,14,13,( ),( ),( )(3)1,2,2,6,3,18,4,54,( ),( )(4)7,14,10,12,14,9,19,5,( ),( )(5)3,1,6,2,12,3,24,4,( ),( ),( )(6)2,3,4,5,8,7,16,9,( ),( )3、先找出规律,在括号内填上适当的数。(1)5,9,17,33,65,( ),( ),( )(2)1,1,2,3,5,8,13,21,( ),( ),89(3)2,3,5,9,( ),33,65.(4)1,3,7,15,( ),63,127(5)1,4,9,16,25,( ),( ),64,81