all depends what these sizes are... what IS "60" ??? assuming these are all reliably the same units and you're not suddenl;y going to have to deal with "10M" or something, i'd just say use awk, tis a doddle
Code:
awk '{ if ($1 > 100) print }' list
i.e. print all lines who's first field is larger than 100 from the file "list"