3.8×99+3.8 2.8+4.36+5.64 [×(-)]÷
x∶(1-40%)=24∶3
7×8÷7×8= 0×0.35+3.5= +=
×+×= 0.52= 6×3.14=
①1375+450÷18×25 ②41×25%+×60-0.25
③ ④17.8-
⑤ ⑥