Please teach me how to Mapping Function [counter]

[Shuto_Suzuki]

Hellow, Every one.
My Name is Shuto Suzuki.

Please teach me how to Mapping Function [counter].


When I actually tried setting the mapping definition as above, the output result for ① was 202.
This can be understood by saying,
　``The value of [Increment] was added to the value of [Initial Value] for the number of calls of [counter].''


However, regarding ②, in parts (1) and (2) of the image,
I thought that both would be 420 because "counter" was called twice,
but the result was 210 for both.

Not only the above example ,even other simple mapping examples is okey.
Please teach me about to know how the "counter" function works.

example)
With this kind of mapping, [Initial Value] is this value and [Increment] is this value, so it is calculated like this and the output result is like this.  etc

Best Regards.