How to perform calculations in the datagridview & outside

Dear Experts;

 

I would like to know if there is a way to perform calculations in unbound control inside the datagridview & unbound control created outside the datagridview.

 

Example 

 

we may have the columns for both Debit (Dr) and Credit (Cr) and the total at the bottom.

 

 

Regards

 

Chris