1 - 1/2+1/2 =
1/4 - 1/2x1/2=
5/6 - 1/2+1/3=
2/6 - 1/2x2/3
1/2 - 1/6:1/3=
2/5 - 9/10-1/2=
3 - 1:1/3=
1/6 - 1/3:2=