1÷=
1÷×7=
0.8×50%=
÷=
2-=
16÷50%=
1-+=
25%×4=
25%× + ×25%
( - )×48
12×( +)
2.8×25+12×2.5
X-80%X=0.4
X+ =
X+ 25%X=25