Simple calculations on pdf fillable form

I have an excel spreadsheet which contains simple calculations but it seems not working on pdf fillable form with custom calculation script?

can anybody help me to get rid of this issue?

Actually, I am doing this calculation on a filed but don't know to achieve this figure result in field

100*(1+25%)

So, 25% field can be read-only or not visible but this will not calculate the result of 125?

Here is the code I am using:

// Get first field value

var v1 = getField("pay rate").value;

// Get second field value

var v2 = getField("Text2").value;

// Set this field value equal to the difference

event.value = v1 * v2;

I am hiding 25% filed as this will remain same and do not need to show.

Here are excel sheet and pdf form

I am attaching excel sheet and pdf file for reference.

Thank You in advance!