计算题0.258×447+258×0.678-25.8×1.25 4.52×1.5+4.48÷-1.5
7.09×+0.225×6-60%×0.64 (+)+(+)
×- ×0.75+0.8×+×
÷[-4.5×(20%+)] 7+14+21+28+…+777+784
[(77+)×(1-)-1.5]÷0.2 ×3+×25+×
6.37×1.25-+4.63×125% ×[0.75-(-25%)]÷1.25
×+×+×+× (2-1÷2)×(2-2÷3)×(2-3÷4)×……(2-2002÷2003)
1+++……+ -+-+-
×+×+×+× (++)×(12×-2×+4×)
+++……++ [1-(1-0.5×)]×12+27÷214×49×12÷××12