The problem is basically asking you to approximate the square root of numbers that are not perfect squares. You should be able to recognize that 54 is very close to 49 and you should know that the square root of 49 is 7. You should also know that the next perfect square is 64 (whose square root is 8). Therefore the square root of 50 is between 7 and 8, but closer to 7 since 50 is closer to 49.
