八字宝塔

珠算趣味算题。它由九个加、减、乘混合算题的结果排列组成:9×9+7=88;9×98+6=888;9×987+5=88889×9876+4=888889×98765+3=8888889×987654+2=88888889×9876543+1=88888888;9×98765432+0=888888888;9×987654321-1=8888888888;在进行计算时也可采用简捷算法,如:9×9876543+1=( ......    （本文共 262 字 ）     [阅读本文] >>