To find the sum of all the prime numbers between 1 and 10, I need to first identify which numbers in that range are prime. A prime number is a positive integer that has exactly two factors: 1 and itself. The number 1 is not prime, because it only has one factor: 1. The number 2 is prime, because it has exactly two factors: 1 and 2. The number 3 is prime, because it has exactly two factors: 1 and 3. The number 4 is not prime, because it has more than two factors: 1, 2, and 4. The number 5 is prime, because it has exactly two factors: 1 and 5. The number 6 is not prime, because it has more than two factors: 1, 2, 3, and 6. The number 7 is prime, because it has exactly two factors: 1 and 7. The number 8 is not prime, because it has more than two factors: 1, 2, 4, and 8. The number 9 is not prime, because it has more than two factors: 1, 3, and 9. The number 10 is not prime, because it has more than two factors: 1, 2, 5, and 10. So the prime numbers between 1 and 10 are 2, 3, 5, and 7. To find their sum, I just need to add them up: 2 + 3 + 5 + 7 = 17. 
What is the sum of all the prime numbers between 1 and 10?