□□□÷9=18…□,余数填 才能使被除数最大.
6440÷ =28.
÷=19× =+ = ﹣=1.
根据5.6×2.3=12.88,那么1.288÷0.56= ,128.8÷2.3= .
×30=420.
÷ =× =1(a、b都不为零)