For the life of me, I can't get the first part (3 and under) with using one of the round functions, but this should do it...
Let me know how this works out for you...
Code:
-A-- -B--
1 0.00 0.50
2 0.5 1.00
3 1.00 1.50
4 1.5 2.00
5 2.00 2.50
6 2.5 3.00
7 3.00 3.00
8 3.10 4.00
9 3.40 4.00
10 3.57 4.00
11 3.77 4.00
12 3.97 4.00
13 4.17 5.00
14 4.37 5.00
B1 copied down =IF(A1<=3,LOOKUP(A1,{0,0.5,1,1.5,2,2.5,3},{0.5,1,1 .5,2,2.5,3,3}),ROUNDUP(A1,0))
Are the value 3 and below perfect values in the .5 increments or could they be 2.6 and such?