在横线里填上“>”,“<”或“=”.270÷(18+9) 270÷18+270÷9 20×52﹣15×52 52×20﹣1559×48 300 990毫升 1升(27+23)×60 27×60+23.
: ==12: = %
:16=9: =0.75= %
10: =4÷8== %= 成.
1= ÷10=24: = %= [填小数].
12÷ = :20==0.8= %