I have some OEM hardware and code which produces a word variable containing a current value.
Lets say for this example it's 100 amps.

Now I have modified the hardware so that although 100amps is flowing the hardware only sees
75% of the current so the value in the variable is now 75. A 25% reduction

But what I want is for my gizmo to report the actual current by adding on the 25% to get back to 100amps

How can I do that with the word variable? Multiplication factor?

Adding on 25% to 75 does not give 100 of course so how can I do this?

The variable can be between 0 and 10,000.