I've always understood the importance of mental math and computation strategies, but I'd never really understood how to teach it. It felt like something kids either had or they didn't. This year, however, I decided that we'd start doing number talks from day #1, and I'm already blown away by how my students are developing as mathematical thinkers. They're able to solve complicated addition problems in their heads -- no paper allowed -- and they're articulating their strategies well. I've been introducing a new strategy every 2-3 days, and it's been awesome. We'll be moving on to subtraction strategies in a few days, and I have high expectations for that to.

To help students with the mental math strategies, I made a set of posters that describe each strategy with an example of how it works. There are 20 posters in all -- one for each strategy described in the book.

The complete set is available in my TpT store, and they'll be on sale for 28% off this weekend as part of the Teachers Pay Teachers back to school sale if you use the code

**BTS13**.

As I've been working on order of operations and number sense with my fourth graders, I also introduced the four fours problem. The premise of the problem is this:

Using some arithmetic combination of four 4's, can you write an equation for each of the numbers from 1-100? Here are the rules:

- You may use any combination of addition, subtraction, multiplication, and/or division
- You may combine numbers, e.g., use 2 of the fours to make the number 44
- You may insert decimal points
- You may use a four as an exponent
- You may use square roots
- You may use factorials, e.g., 4! is equivalent to 4 x 3 x 2 x 1 = 24
- You may use overbars to make a decimal repeat
- You may NOT use any digit other than a four
- You MUST use all four 4's in each solution

Before I go on, let me give two caveats. 1) I didn't expect all of my students to be able to handle all of these rules. Square roots, exponents, and factorials are WAY above my fourth graders heads generally, but I did have a handful that could handle it. And there are plenty of solutions to be found that don't require those operations. 2) This problem freaked out the parents more than it scared the kids, I think. I had a few panicked parents that I had to talk down while we were working on this, but in the end, it was well worth it. My students were so excited about math and problem solving as we worked through this problem. It was homework each night to try to find a few more solutions, and then we'd add to a chart during math class. Look at all that my students accomplished after just two days!

We've filled in a bunch more solutions since then, but of course I left my camera at school this weekend...

Finally, in honor of the big back to school sale on TpT, I've bundled four of my favorite math resources into a back to school math pack for this weekend only.

Sold separately, this is $17 worth of products that I'm selling this weekend for $10, but after Monday, the bundle will no longer be available in my store. So if you've had any of these on your wish list...

Hope everyone had a great week! I'm still learning how to juggle grad school with teaching, but I'm hopeful that I'll still be posting at least once a week.

Off to start catching up on blog reading and filling my cart for the TpT sale! Have a great weekend!

Oh what fun! The four 4's would be fun to do as extra credit or a game in a high school classroom!

ReplyDeleteThat math challenge is amazing! I had to see the picture to really understand but I think it would be a lot of fun.

ReplyDeleteJennifer

Mrs. Laffin's LaughingsUm, wow! That math challenge is impressive!

ReplyDelete