I used Microsoft Word and typed (in 250 font) an F and then went to "font" and clicked on "outline" to get a block letter. I made them large enough that I got 4 on a page. I ran them off back to back so that the students had 8. I did the same for the letter M.
GCF:
I started off my lesson with a quick reminder that factor + factor = product. Then we looked at the multiplication chart on the wall and just called out factors of a given number. Then I passed out the page with the block letters. At the bottom of the F, write down a number. Then in the upper parts of the F, write out the factors. The teacher who originally did this used an arrow to link the two lines. The class and I did the front side together, they did the back side in partners. We did the guided practice problems in our book together. When it came time for independent practice, they were ready.
LCM:
I did Jennifer Runde's math journal page with the "egg-cellent multiples" and reminded the students that multiples are skip counting. We discussed how the GCF is finding factors that numbers have in common, and the LCM is finding the products that numbers have in common. Our next activity was to take term LCM and do the Frayer Model and really get what the term means and what it looks like. I also lifted this from another teacher (not sure who it was though, will come back and tag when I locate). Then we did the block M page. Again, 4 on the front, 4 on the back, 4 together, 4 in partners. As with the GCF lesson, the LCM lesson took a couple of days and lots of practice. Using the block letters and all the journaling really helped the students understand each term and they could apply it without mixing the two.
