DateTimePicker help

Hi I am in college and have no idea how to do this. So with out using a function are a different class, how would I write the code to increase the date by three days.

for example textbox1.text = 3 + 5
when I run the forum textbox1.text would be 8

now if it want to add the datetimepicker + 3 days what would it look like?
I have tried already
textbox1.text = datetimepicker.value.days + 3
and alot of other things but they all are a no go.

If you can do it without using a module or a function I would really appreciate it.

Sub A1A1()
'DateAdd(interval, number, date)
MsgBox DateAdd("d", 3, Now)
End Sub