2的分数单位是 ,它至少要加上 个这样的分数单位才能化成整数.
=2: =4÷ = %=0.2.
12÷ = :12=0.75= = %
0.75=6÷ = :12== %
1.75=7÷ ==28÷ =.
= ÷60=2:5= %= 填小数.