9时30分,钟面上的时针和分针形成的较小夹角是直角. .(判断对错)
5:13==1.2: .
9÷ =0.6= :20=30: .
= :15==6÷ = (填小数)
:8=15÷ ==9: .
==12÷ = :20= (小数)