If we form numbers by entering digits in row or column wise in calculator numpad the resulting number is divisible by 3 exactly two times not more or less than that. Lets consider this numpad
7 8 9 4 5 6 1 2 3
Rule 1 Pattern should be same while choosing digits from the rows or columns. Suppose we are choosing digits row wise So if we take 1st digit of a row then 3rd and then 2nd digit of that row, then for other two rows we must take 1st digit and then 3rd and then 2nd digit. For example we can take 213546879 it is divisible by 3 exactly two times. Similarly if we choose column wise 396174285 it is also divisible by 3 exactly two times. But we can not take 546312789 here we took 2nd digit "5" from 2nd row then 1st digit "4" and then 3rd digit "6". But then we took 3rd digit "3" from 3rd row instead of taking 2nd digit "2". And therefore 546312789 is not divisible by 3 exactly two times. It is divisible by 3 three times. Rule 2 Either we can select all digits row wise or column wise. It will not work if we choose numbers randomly like 753489621 is divisible by 3 four times and 753162489 is divisible by 3 three times.
So if we form a number by selecting digits from rows or columns in same pattern the number is always divisible by 3 exactly two times not more or less than that. Here are few more examples
174396285 978645312 417639528 132798465