2100平方分米= 平方米,300米= 分米= 厘米.
3÷4= (填分数)= (填小数)
= ÷ == (最后一空填小数)
1.75=7÷ = =28÷ = .
: =2= ÷10= %
= ÷ === 0.41 (填小数)