multiply method
Multiply: this.value * value
Implementation
num? multiply(dynamic value) {
  var result = parseNum(_value)! * parseNum(value)!;
  set(result);
  return asNum;
}Multiply: this.value * value
num? multiply(dynamic value) {
  var result = parseNum(_value)! * parseNum(value)!;
  set(result);
  return asNum;
}