It seems as if you have 2 choices:
1) if you keep your numbers as text (which looks nice, but which I don't
recommend), you need to add leading zeros to them to make sure they all sort as
you want:
http://delphi.about.com/od/adptips2005/qt/leadingzero.htm
or, 2) force your number field (fieldtype FLOAT) to contain/show two decimal
places:
FloatToStrF(FLOAT,ffFixed,15,2) = 2 Decimal
valuesFloatToStrF(FLOAT,ffFixed,15,3) = 3 Decimal Values
etc...
http://windowslive.com/howitworks?ocid=TXT_TAGLM_WL_t1_hm_justgotbetter_howitworks_012009
