八字寶塔
世界珠算

        珠算趣味算題。它由九個(gè)加、減、乘混合算題的結(jié)果排列組成: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;在進(jìn)行計(jì)算時(shí)也可采用簡(jiǎn)捷算法,如:9×9876543+1=(    （本文共 262 字 ）     [閱讀本文] >>