(1)63×60%+×37 =×(63+37) =×100 =60 (2)50%×2.5××64 =(×2)×(2.5×4)×(×8) =10 (3)6.73-2+(3.27-1) =(6.73+3.27)-(2+1) =10-4 =6 (4)7-(3.8+1)-1 =6-5-(3.8+1.2) =6-5 =1 (5)13-(4+3)-0.75 =13-3-(4.25+0.75) =10-5 =5