VB uses implicit conversions when possible, whereas many languages require explicit casting. To "paint a numeric field on a form", either put it in a text box or label, or use the print statement, which will put the result directly on the form.
Selimsl's response is recommended but not required. You can use a string value directly in a math calculation, and VB will implicitly cast your string. One of the problems: "10" - "5" evaluates to 5, an integer. "10" + "5" evaluates to "105", a string. This is because + is overloaded in vb both as a string concatenation operator and an addition operator. Since VB doesn't have to recast the operands to make sense of the operation, it doesn't.
This is why it's a good idea to do as selimsl suggests.
If you want to avoid implicit casting altogether, use the conversion functions. CStr will convert to a string.
HTH
Bob
If you want to convert the input value to a string