①6.4×2.5×1.25
②8.5×98%
③÷4+×
④×
83﹣57=
1﹣0.74=
=
0.25×40=
2.1× =
0.15÷0.5=
①3.25×3.6+7.75×3.6﹣3.6
②9.9×25
③
④
①2021÷1.25÷
②5.74×12.5%+1.26÷8+
③(-0.6)÷(-)
④0.8÷[(+)×]