txtItemPrice must be a numeric on my form

How will I add this to my database or do calculations on it, ensuring that it is saved as numeric and not as text....

Insert into database....

insert into client values txtItemPrice

or

insert into client values " & txtItemPrice & "

or

???

Calculations....

intTotal = txtItemPrice + txtItemVat

or

intTotal = "txtItemPrice" + "txtItemVat"

or

????