A pattern uses alternating addition and subtraction as its rules. The rules are "Add 7" and "Subtract 3." The pattern begins with 37. What is the 5th number in the pattern?
Starting with 37, the pattern follows the rules "Add 7" and "Subtract 3" alternately.
37 + 7 = 44 (First step, add 7)
44 - 3 = 41 (Second step, subtract 3)
41 + 7 = 48 (Third step, add 7)
48 - 3 = 45 (Fourth step, subtract 3)
45 + 7 = 52 (Fifth step, add 7)
Therefore, the fifth number in the pattern is 52. Answer: \boxed{52}.