199.9*19.98-199.8*19.97用简便方法计算（要过程）.

199.9*19.98-199.8*19.97 199.9×19.98-19.99×199.8用简便方法怎么计算 199.9×19.98-199.8×19.97(简便计算,递等式)给好评. 第一讲全部答案,2000×199.9-1999×199.8 19.98×37-199.8×1.9+1.998×820 9.56×4.18-7.3×4.18-0.26×4.18 199.9*19.98-199.8*19.97用简便方法计算（要过程）. 199.9×19.98-19.98×1.987 简算 2000×199.9-1999×199.8 19.98×51+199.8×3.9+199.8是多少 计算 199.8+19.98+1.998+2.222 199.8+19.98+1.998+2.222的简便方法? 1998+199.8+19.98+1.998+2.222= 199.8+19.98+1.998+2.222 要过程 19.98×37-199.8×1.9 1998×0. 1998+199.8+19.98+1.998简便算法 199.9×29.98-19.99×199.8求简便计算 2000*199.9-1999*199.8 简便计算 2000×199.9-1997×199.8的简便计算 19.98*37+199.8*2.3+9.99*80=简算