The .Tag property is a useful little item that all controls have. It holds type Object, so it can hold anything you want it to hold. However, if the plan is to have a second textbox (a label would be better, since the user can't change the information, supposedly) beside the first, then the .Tag isn't needed. You could go into interesting contortions on this, but with only five items, it barely matters.

Vexslasher has one example, except that you need to be using Decimal rather than Integer. Double would also work, except that you sound like you are dealing with currency, so Decimal is more appropriate.