Day 12: Greatest Common Factor

6th Grade Math Standards: 6.NS.4 Find the greatest common factor of two whole numbers less than or equal to 100 and the least common multiple of two whole numbers less than or equal to 12. Use the distributive property to express a sum of two whole numbers 1–100 with a common factor as a multiple of a sum of two whole numbers with no common factor. For example, express 36 + 8 as 4(9 + 2).
MA.4.a. Apply number theory concepts, including prime factorization and relatively prime numbers, to the solution of problems.

The Learning Objective: Determine the greatest common factor of two or three numbers

Quote of the Day: “Nearly every person who develops an idea works at it up to the point where it looks impossible, and then gets discouraged. That’s not the place to become discouraged...Our greatest weakness lies in giving up. The most certain way to succeed is always to try one more time. Many of life’s failures are people who did not realize how close they were to success when they gave up.” - Thomas Edison

Assessment: After showing the students the first two examples in the notes, they did the next two problems on their own. I also had the students do the first two problems in the homework and checked them off. If students completed these problems without any major issues I had them cross out two more problems (which I picked since they were more of the same). Finally I had students write their divisibility rules in the journal to see what they were struggling with. The rule for 4 was giving them the most difficulty.

Agenda:

1. I checked homework while students did estimation
2. Review homework
3. Greatest Common Factor Notes
4. Divisibility Rules in the Journals
5. Greatest Common Factor Homework
6. Greatest Common Factor Challenge (students had the option of doing this on the homework and skipping another homework problem) 

Glass Half-Full Take: Estimation 180 always gets more involved by the third question in terms of the level of thinking on a particular topic (today it was toilet paper).

I also liked a question that a student asked me. What happens when we're trying to find the greatest common factor of two prime numbers?

The challenge problem added some differentiation to the lesson for students.

Grace was supposed to find the greatest common factor of 330 and 462, but she found the greatest common prime factor instead. What is the difference between the number she found and the number she was supposed to find?

One Regret: I had the students sitting in their desks for too long. I have to break that up somehow. Perhaps a vocabulary review or perhaps I could challenge them to show a mistake to a friend. Something needs to be done to keep them active and awake.

Homework: See agenda #5 above (in addition to the weekly quiz).