There is no easy rule for testing divisibility by 7, but one can use the trick of repeated subtraction (i.e., divide the number by 7, subtract the quotient from the original number, and repeat the process until the remaining number is less than 7).
There is no easy rule for testing divisibility by 7, but one can use the trick of repeated subtraction (i.e., divide the number by 7, subtract the quotient from the original number, and repeat the process until the remaining number is less than 7).