Well, I did the easy bit. I got the answer with an incredibly small piece of code, but I'm far too stupid to get it to display all the decimal places.

Code:
Option Compare Database
Option Explicit

Dim blnStop As Boolean

Private Sub Command3_Click()
Dim storage

On Error Resume Next

temp.Caption = 2

Do While blnStop = False
    DoEvents
    temp2.Caption = ""
    storage = ((Val(Value.Caption) / Val(temp.Caption)) + Val(temp.Caption)) / 2
    current.Caption = storage * storage
    temp.Caption = storage
Loop

End Sub

Private Sub Command5_Click()
    blnStop = true
end sub
How would I go about getting it to display all the decimal place.

PS - I'm using VBA in Access as I'm at work, which is also why I don't have time to race people to the answer, sorry...