error changing the data type on a table from text to number

[IT_Charlies]

the table i have, all the fields are in text data type. i need to change only one of the fields from text to number. when i try to it gives me a message that says "the setting for the fieldsize property of one or more fields has been changed to a shorter size. if data is lost validation rules may be violated as a result. do you want to continue?" i click yes then it tells me "there isnt enough disk space or memory" i click ok then it says "errors were encountered during the save operation"



what am i doing wrong or how should i change it?
thanks in advance for your comments, suggestions and ideas.

[June7]

Don't know, would have to examine the data. If you want to provide file follow instructions at bottom of my post.