I'm new to Android so please, explain me, how to use BigDecimal in API level 16, because using this line:
BigDecimal currentNumber = new BigDecimal(String "0.0");
results in an error, Call requires api level 24.
you are constructing the object wrong... BigDecimal is available since API1
you need to do:
BigDecimal currentNumber = new BigDecimal("0.0");
Note that I removed the unnecessary String Class just pass the value between quotes...