How can you tell that 479 divided by 6 will have 2-digit quotient?

Answer 1

479 is greater than 60 and less than 600.

6 X 10 = 60 and 6 x 100 = 600. Thus, the number of "6"'s that will divide into 479 has to be somewhere between 10 and 100...which leaves only 2-digit numbers.