For this activity you'll need a printer OR graph paper. If you chose the printer, print out this page, follow directions, and cross off the numbers that you are instucted to. If you chose graph paper, copy this Sieve and cross of the numbers that you are instucted to. This is what the sieve looks like:
First you cross off the numbers that I tell you to.
Cross off the number 1.
Cross off every even number, but not 2.
Cross off every third number, but not 3.
Cross off every fifth number, but not 5.
Cross off every seventh number, but not 7.
All the numbers that are not crossed out are PRIME NUMBERS!