datagrids - extra column

Hi,

I fill a datagrid with data from some tables. Now I want an extra column wich contains the outcome of a multiplication of two other columns, For instance:

columns 1 and 2 contain data from datatables:

(number) (price)
2 13

I want a third column:

(number) (price) (to pay)
2 13 26


Can Anyone help me with this?

Thanks, kleedje

do like this

VB Code:

'da is an Sqldataadapter
Dim dt As DataTable = New DataTable("sampletable")
        da.Fill(dt)
Dim dc As DataColumn = New 
DataColumn()
        dc.ColumnName = "mzim"
        dc.DefaultValue = " "
        dt.Columns.Add(dc)