7÷22= (用循环节表示)≈ (精确到0.01)
:12=:=0.3÷ == %
=5:8= %= ÷32=0.625.
4÷ == :15== %=( 小数)
12: ==0.6=48÷ .
:30=30÷ === (小数)= 折.