0.77+1.23=224×25%=64.8÷0.12=401.1÷1.1%=100
0.65÷13=0.05356-199=1571.87+2.3=4.170.375÷[1/8]=3
20÷40=0.55÷([1/2]+[1/3])=615÷0.25=6010-0.64=9.36
3.14×202=12561÷[13/54]×[13/54]=172÷2.4=30x:[1/2]=[3/4],x=[3/8]
18÷27=[2/3][1/3]-[1/5]=[2/15]99×[1/4]+[1/4]=25化简比:280:84=10:3