Cory made a complete list of the prime numbers between 1 and 25. What is the sum of the smallest prime number and the largest prime number on his list?
A prime number is a natural number that has exactly two positive factors: 1 and itself. The smallest prime number is 2, since 1 is not considered a prime number. The largest prime number between 1 and 25 is 23, since 25 is not prime (it is divisible by 5). To find the sum of the smallest and largest prime numbers on Cory's list, I just need to add 2 and 23. I can do this mentally or with pencil and paper: 2 + 23 = 25.

