4,8,14,23,36,( 49 51 53 54
4,8,14,23,36,( 49 51 53 54
35+36-37-38+39+40-41-42+43+44-45-46+47+48-49-50+51+52-53-54+
46、47、48、49、50、51、52、53、54、55
48 49 50 51 52 53 54题
(48)(49)(50)(51)(52)(53)(54)(5
12,13,14,15,21,23,24,25,31,32,34,35,41,42,43,45,51,52,53,54
用简便方法计算49+51+53+47+48+50+49+52+46+51+54+55+51+53+47+50+49+51
50,21,36,98,54,31,27,68,93,23,87,96,53,47,29,74,80,60,49,81这
49/51×23 简算,
找规律算一算49+53+47+48+51+54+52+46=
第46,47,48,49,50,51,52,53,54,55,56,57
45 46 47 48 49 50 51 52 53 54 55用简便计算怎样做