(1)50的7倍是多少?50×7 (2)50个7是多少?50×7 .
40: =8:10= /5= (填小数)
=18: = ÷40= [填小数].
==10÷ = ÷36.
:16= ÷ ==0.125.
a÷b=,那么=. .