to echo others comments
store the values in a column of the appropriate type
so dates in datetime columns
numbers in an appropriate numeric column. (intgers in an integr type (tinyint,bigint,integer)
..and so on
formatting a column can be done when you extract the data eitehr in the query or the data consumer
with dates there is another especially good reason to use the datetime datatype and that is you can make use of the date time functions built into MySQL
MySQL :: MySQL 5.5 Reference Manual :: 11.7 Date and Time Functions
right now you may only need the date values to appear on a report, but who knows if you may want to, say do a summary report based on month or year.
who knows if you want to only extract data for a specific month or a specific time period. storing the values in their proper datatype now elimiantes any possible problems down the line.