同学们种树,每个同学种3棵,21棵树要几个同学才能完成?4|.^:P(I7\2j;r5}8l3`1l8y(g*H
算式:提示0n'`1}*X3G.@4R2w-g7K'C+[:|,^3U4|.^:P(I7\2j;r5}8l3`1l8y(g*H
答:21棵树要8i)J'r:_:~.d7x0g*e'|-m5m(f7i:L-s*M1\个同学才能完成。4|.^:P(I7\2j;r5}8l3`1l8y(g*H