Counting a variable whose value is derived from other live values constantly changing.

I have a live input of numbers (from a live constantly changing source) say in cell A1 . Every time the number in A1 changes( it may be + or - but it will be different from the previous number), I want to add 1 in the cell B1( and keep adding in B1 as the live input keeps coming and changing in A1 ). can some one help?
Someone nice helped me with this formula….


Private Sub Worksheet_Change(ByVal Target As Range)

If Target.Address = Range("A1").Address Then
Range("B1").Value = Range("B1").Value + 1
End If
End Sub

The above formula is great but it works only if a data is directly inputted in the cell A1. If A1 = c1-d1 , then the values don’t change in B1 and in my case the live values are coming on cell C1 and D1 from where live difference is constantly updated in A1.
Please help me with a solution. Thanx !

Tons of thanks .. you are a wizard !

What if you needed to introduce similar values in a1 & b2, and a2&b2 (in the same sheet ?

Thanx a ton ! God bless you.... I would like to keep in touch with you for what this means to me is just beyond anybodys imagination.
Thanks again

Suppose in cell C1 is the price and D1 is the volume of a certain scrip.
Every time the price goes up( ie C1>OLDC1), in cell B1 we add 1. Concurrently in the cell A1 we add the Volume( D1-Prev D1)
Every time the price goes down( ie C1<OLDValueC1), in cell B1 we add -1. Concurrently in the cell A1 we add the Volume( D1-Prev D1) in a negative value=-(D1-OLDValueD1)
How can we write this for 2 pairs ?
It will be so kind of you to help me out.

Many Thanks to Jakobshavn who solved this big problem with supremacy !