When my husband (formerly an Australian maths teacher) and I were dating, he wrote a blog post where he shared how he used the Sieve of Eratosthenes with students.

I was blown away by this post because I’d used this activity with students before but never exactly like the way he explained. Shaun didn’t just have students mark out a number once. He had them color-code their work and mark out numbers each time they were a multiple of one of the prime numbers.

My math concepts students are currently working on prime vs. composite numbers, so I finally got to try this activity out for myself with this multi-colored tweak. It was awesome! I also appreciated that Shaun has his template extend to 150 instead of the standard 100 often used in math classes.

## More Activities for Teaching Prime and Composite Numbers

Tpaquette

Monday 22nd of January 2018

Any chance I could get a copy of the Slope Art Project you referred to in #1? If not no worries, I just like to try new projects sometimes. Sincerely,

Tracy

SiouxGeonz

Saturday 20th of January 2018

THank you for that hundred chart! I *promise* you some of those ninth graders will really benefit. (Thanks for getting one that just looks like a number chart... no puppies...) I'm working on a geogebra exercise for practice just putting numbers on a number line to get more fluent with associating numbers with what they mean...