北师大版 五年级上册 数学好玩,像笑笑这样摆10个三角形需要多少根小棒？,3,5,7,9,1,2,3,11,13,15,17,19,21,3,32,322,323,324,325,326,327,328,329,3,231,332,433,534,635,736,837,938,1039,12,122,123,124,125,126,127,128,129,1210,笑笑接着摆下去，一共用了37根小棒，你知道她摆了多少个三角形吗？,37334,34217,17118,37136,36218,观察每个点阵中点的个数，你发现了什么？,11,1,2,3,22,33,44,55,13,135,1357,1,121,12321,1234321,1,
