4*6*8+6*8*10+8*10*12+.+24*26*28=?
2+4-6+8-10+12-14+16-18+20-22+24-26+28=?
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
(口算)4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36.
数字推理:8,6,10,11,12,7,( ),24,28
1+2+3-4+5+6+7-8+9+10+11-12+.+25+26+27-28
1+2+3-4+5+6+7-8+9+10+11-12+···+25+26+27-28=?
1+2+3-4+5+6+7-8+9+10+11-12+.+25+26+27-28=?
若干个偶数按每行8个数排成一行:2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,
2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,数字6个1组.点组
1,2,4,6,8,10,12,14,15,16,20,21,22,24,25,26,28,30,32每6个数一组,最多
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40圈的是6,
2+4+6+8+10+12+14+16+18+20+22+24+26 简算 要 过程