1袋面粉重50千克, 袋面粉重1吨.3千克鸡蛋6元钱,1千克鸡蛋要 元.
=42: =75%= 折.
=20: =0.625= ÷40= %
.
10: =0.625== ÷32= .
0.75== %= :12= 折.