0.78×98
12.5×3.9×0.8
4.6×3.7+6.3×4.6
①9.1÷0.13÷0.25
②1.8×25+24÷1.5
③(18.6+12.6)÷4
①6.4×2.5×1.25
②8.5×98%
③÷4+×
④×