## 29 March 2012

### Fun with Factoring

Factoring ... fun?  Today it was!  We had a three-part math lesson on factoring and prime factorization today.  We did a great hands-on lesson from my newest math resource - Zeroing in on Number and Operations (check out the link at the bottom of my post).

We've been working on prime and composite numbers, and factors and multiples this week (I've got some FABULOUS foldables to share with you on Sunday).

Today we started with reviewing the definitions for prime and composite numbers, factors, and prime factors (we used our foldables from the week for this).  We then used the smartboard to roll the dice to form a two-digit number and list the factors for the number.

For the minds-on part of the lesson we examined the numbers and shapes I had taped to the board.  The students observed that they were all examples of prime numbers.
I then showed them a paper bag that I had written a number on (I started with 10).  I asked the students how many shapes I had in the bag if the bag had a product of 10.  Right away the students were able to answer "two shapes".  The shapes had a value of 2 and 5.  The funny thing was, even though the students were multiplying the numbers together to get 5 x 2 = 10, they kept saying "adding" instead of multiplying when justifying their answers (must FIX that immediately).  We repeated the concept for 28 and 50, which were more difficult numbers because each bag held 3 shapes (3 prime factors).  This part was done as a whole group activity.

We (I keep saying "we" because I'm part of a special PD team for three-part lessons.  Myself and another teacher (grade 2/3) team teach these lessons.  Over the course of the year we do 6 half-day lessons in my room, and 6 half-day lessons in her room) then divided the class into similar ability pairings and presented this question (and a bag with a product of 300 written on it).  Students worked together to find the answer.  Some students used a factor tree to find their answer and were finished quite quickly (I gave these students a second, much harder, number to work with if they finished quickly).  Other students worked through an "educated" guess and check strategy.  In the end, all students came to the correct answer, some just got there quicker than others.

We then grouped all the students' answers on the board for our bansho activity (to read more about the Bansho strategy, click HERE).  Basically, we had two groups for our bansho activity - students that used a factor tree to find the prime factors, and students who didn't.  While the pairs were working on their solutions, we circulate around the class recording questions we have for the students, or noting students whose strategies should be shared with the class.  Here are two examples of different strategies used by my students.  Do you see the green dots in the right hand corner of their papers?  When students finish a minds-on activity, they need to put a traffic light comprehension dot on the corner of their papers - green is for no problems, yellow is for some difficulty / questions, red is for a lot of difficulty / questions.  It's a quick and easy way to students to reflect on their work.

Students had an independent work sheet on this concept when we completed the activity (from the book at the top of the page).  They will hand in their work tomorrow (formative assessment) so I can plan from there.  But from what I saw today, I'm thinking (hoping) we'll see some great success.  I can't wait to use more activities from this book!

Happy Thursday!!!

1. I am just curious- when you team teach do you put both classes together? We are encouraged to do more team teaching but we are finding it difficult with classes of 30+. Great resource~thanks for sharing!

1. No, we just do one class at a time - we get a supply teacher for 1/2 the day. Teaming up classes would be a neat idea, but I'd have to be working with another teacher closer to my grade for it to really work, I think.

2. Sounds interesting. When you have tried other activities please post how they have gone. I am curious. I am always looking for new ideas for teaching Math. So far I am liking the Prime and Composite activity.

Thanks
Joan

1. I will, Joan. I just got this book, and was so excited to find this activity - it was perfect for today. My principal really liked it, and I think she is thinking of getting the full set of books - they have them from pre-k - grade 8.

3. I love the traffic light comprehension dots. Implementing that strategy tomorrow!

1. Jennifer, it's a fantastic little tool. I started using it the day after I saw it (the teacher I team with for these three-part lessons uses it). It's surprising how bang-on the kids are with their self-assessment.

4. I loved your Bansho resource- thanks for sharing! I also love the red, yellow, and green dots- it's such an easy way for kids to self-reflect :)

~Stephanie

1. Thanks, Stephanie. I've done a math congress for years when sharing problem-solving strategies, but this is my first year doing bansho. I like it! And the traffic light comprehension dot is simply genius ... sure wish I could take credit for it. ;)

5. You are my Math twin!!!! I now have no fear to go down to fifth. You'll walk me through teaching math again :) Leave it up to you to find a fun way to teach factoring!!!! Those kids are so lucky to have you!!!

❤ Mor Zrihen from...
A Teacher's Treasure
Teaching Treasures Shop

1. You are too sweet, Mor! Stick with your foldables and you'll have them eating out of the palm of your hand ... (hopefully you don't have any biters).
Can't wait to teach "with you" next year ... LOVIN' this whole collaboration thing ... can't wait to see what GREAT things we'll come up with!

2. I have been using your EDM Smartboard lessons. My students love them (so do I) Thank you for sharing your resources. Do you still use the EDM program? If so, how do you incorporate extra math activities.?

6. Wonderful post. Pinning this for TBA!

7. This is a great lesson! Thank you so much for sharing!
☼Kate
To The Square Inch

8. Great Lesson - my mind is spinning on ways to adapt this for my 3rd graders. Question, I'm still learning Smart Board, how do I get the dice? Is it something I have to create myself? I looked on SMART Exchange, but didn't find it. I'm on my home computer, not sure if it's on my computer at school. Thanks in advance!

1. Thanks, Denise! The dice are already made for you in the gallery. Open up a blank notebook file, click on the gallery button in the sidebar (looks like a picture frame), and search for dice. These dice are with the interactive files. Hope this helps - let me know if you have any trouble finding them.

9. Love this lesson. I teach fourth, but this is so spot on for what we cover. I would love to get that book, but I'm afraid that's going to be the only lesson I can use from it ha! Would you say that it is appropriate for fourth graders as well, in your opinion?

10. Oh, I just saw the link to the fourth grade one, so sorry!

1. lol - I was just going to say they have one for grades 3-4. I've used 3 lessons already, and plan to use a fourth this week. I really like using the book to introduce new concepts - it really has the students thinking and exploring. My principal is going to buy all the books next year so that each classroom has one.

11. I'm a second-year teacher teaching 5th grade, and I have an hour for math. I have lots of kids who hang back and don't contribute, just wait for me to write answers and copy them down (learning nothing in the process). Frustrating! I use lots of foldables, rotations with hands-on exploration activities, discussions about the many different methods to solve problems... STILL, I have blank stares and often hear crickets. How do you keep this moving (so it doesn't take 2 hours!) and make sure they're engaged? I LOVE the bansho technique, but want to make sure I really get bang for my educational "buck" (meaning time, because in teaching, time is money!)... Thanks!

12. I'm doing my first math lesson for my methods class and was having a very hard time coming up with ideas and finding this has been a huge help! Your journal idea is amazing and will totally help get the kids moving a little and hand on rather than just sitting there listening to me possible fumble through my lesson. Thank you so much and I will be telling others about your blog!

13. Love how this activity uses exploration to uncover the secrets of prime factorization! It leads into great discussion about how all composite numbers may be decomposed into their prime factors, as well as constructed through multiplying prime factors by one another (including repeated factors). I just shared this task and your blog with several of my colleagues this morning. Thank you!