Why get so complicated. Simply type one, forward slash, two, space bar (1/2) and let word do the rest. It works for my 2007 version and also when I had 2003. 'Auto Format as You Type' requires to be enabled.
Or- Try holding down the Alt key while you type in 0189 on the numeric pad, then let go of Alt and you should see ½. It doesn’t work if I use the keys on main part of my keyboard so I’m not sure whether this will work on laptop.
Sorry, If I had read the initial entry I would have seen that the problem was 101/2. Pt a space after the ten when you type and then the 1/2, then delete the space for better formatting. Still easier than loking up the symbols.