口算:369500-256900=652000-325600=869500-556900=854000-625600=4512000-4500000=1526000+1574000=
3600÷45×90
(2.5-2.5×0.6)÷0.4
0.5÷[一(一)]
47.3-1.7×5-1.5
2013-1728÷32