String calculateFiatAmount({double price, String cryptoAmount}) { if (price == null || cryptoAmount == null) { return '0.00'; } final _amount = double.parse(cryptoAmount); final result = price * _amount; if (result == 0.0) { return '0.00'; } return result > 0.01 ? result.toStringAsFixed(2) : '< 0.01'; }