We spent a ton of time this week reviewing divisibility rules and prime numbers. My students have REALLY been struggling with this, and I knew I had to take a week from my normal sixth grade curriculum and do a quick review. I started by having them put a foldable in their notebooks that gives the divisibilty for 2,3,6,9, 5 and 10.
After my students got a little more comfortable with divisibility, we took on Prime Numbers.
First in the lesson I showed my students a video of Eratosthenes. He is teh Greek philosopher who is credited with finding that all numbers can be factored into primes. The video focuses on Eratosthenes as a whole person. He is also credited for finding a very accurate measure of the circumference of the Earth using a sundail. Here is the video:
We use a hundreds board and divisibility rules to find all of the prime numbers from 2-100 and color code them on the board.
We add the hundreds chart to our notebooks and complete a sorting activity for prime and composite numbers.
We had to relearn GCF in order to be successful using this concept with combining like terms and the distributive property. I teach LCM and GCF using the prime ladder method as well, so we spent the rest of our week practicing this new concept. I think that combining like terms will be so much easier next week! When I teach LCM and GCF I use a foldable as well. You can read the original blog post I wrote about this lesson {HERE} If you are interested in any of the foldables you can go {HERE}. The lesson plan I use to teach finding the prime numbers on a hundreds chart is also included in the packet. I also have a BUNDLE which includes the lesson plans for each concept, interactive notebook foldables and practice problems. Check it out {HERE}
I would love to hear how you teach these concepts! Please feel free to share below!
When I do Prime and Composite, I use Red and Green colors. Red for Prime, means stop I can't break it down to more factors. Composites are Green, means go I can still break it down for more factors.
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