How do you find prime numbers between 150 and 200?

Answer 1

Write out the numbers 1 to 200 in 20 rows. Cross out 1. Start at 2 and cross out multiples of 2. That would eliminate all the rest of the even numbers. Go to the next uncrossed-out number (3) and cross out all of its multiples. Some of them will already be crossed out. You can stop by the time you get to 15. All of the uncrossed-out numbers are prime.