When data is received via a textbox it is a string. If you need to do calculations on this data then you need to convert the string into an integer.
dim intTotal as Integer dim strPrice as string = "35" intTotal = Int32.Parse(strPrice) + 5
int IntTotal; string strAge = "35"; intTotal = Convert.ToInt32(strPrice) + 5;
Now the numbers can be added together to equal 40.