Many mental math strategies rely on students being able to “jump” tens. For example, 10 more than 28 is 38. The fancy math term for this skill is *counting by 10s off the decade*. In other words, not just counting 10, 20, 30, 40, etc., but also counting 17, 27, 37, 47, etc. Students should be able to fluently count off the decade from any number.

*This post contains affiliate links, which simply means that when you use my link and purchase a product, I receive a small commission. There is no additional cost to you, and I only link to books and products that I personally use and recommend.*

Don’t, however, forget about the concrete–>representational–>abstract (CRA) sequence of instruction. While the goal is to be able to count by 10s off the decade, which is basically rote counting, we also want students to understand the concept. A great way to introduce counting off the decades is to build a number, for example 27, using base-10 blocks. Then continue to add rods as students count by 10s. So they see *why* counting by 10s off the decade works. Why the ones stay the same and only the tens change. Tie this in with patterns on the hundred chart.

A great way to practice counting by 10s off the decade is using one of my favorite routines from __Number Sense Routines__ by Jessica Shumway. The routine is called Count Around the Circle, but it works perfectly when kids are in line, too, like when they’re lining up for recess, waiting in line for the restroom, etc. You start with a number, say 14, and proceed around the circle counting by tens. So the first child would say 24, then the next would say 34, etc. When you get around the circle, you can start back around counting backwards by tens! I like it better than choral counting, because each child knows they are going to participate. Of course, you want to have supports, like a hundred chart, for students who might struggle.

The __Graphics From the Pond__ ghosties are back for one last hurrah before I close the books on Halloween.

Click __here__ to grab your freebie.

We’re learning multiples and this will be a great practice. I also love the activity Counting in a Circle. Wasted time is a big irritant and I am always trying to come up with a way to review/reinforce concepts during these times of transition/waiting.

Thanks for sharing. I like the counting the circle idea.

You’re welcome! Count Around the Circle can be done in so many ways, and the kiddos really enjoy it. 🙂

Another great freebie!!!! Thanks a bunch!! 🙂

Live Laugh and Love to Learn

You’re welcome, Lisa! 🙂

Hi Donna,

Thanks for the neat activity for counting by the decades. I have started a new blog but I have been focusing on Common Core math for several years. I would love to share these freebie with you for using ten frames. It has a candy corn theme. Here is the post.

http://idreamoffirstgrade.blogspot.com/2012/10/candy-corn-ten-frame-math-1nbt-and-kcc.html

Thanks for all your great ideas. I have been checking out your blog for awhile.

Sarah

Very nice freebie! Thanks for sharing. I’m a new follower of your blog now. 🙂

Hi Donna, I used the skip counting freebie and the monster hundred chart addition freebie this morning in class. Then I pulled out the hundreds charts and just threw some problems at the kids as I used my ipad/apple tv to display all the different ways they were using the hundred chart (with highlighters) to solve the problems. It was really fun and I saw lightbulbs going off.. they started challenging each other to see who could solve the problem the fastest. It was a lot of fun, but good work on developing that number sense. Thanks so much for the great resources!

Deb, thanks so much for taking the time to comment! It’s so exciting to hear such great things going on in math instruction. So cool that you just gave it a try and that they responded so well. 🙂

i love this Donna! We do this all the time in calendar, but I’d love to see how my kids can do on their own!

Amy Burton

I agree, Amy! It keeps them engaged, too, because they know their turn is coming. 🙂

You’ve suggested a lot of great books. I actually own this one. 🙂 I do love it.

❀ Tammy

Forever in FirstIt’s a good one, right? 🙂

Thanks for the activity suggestions, as well as the ghost skip counting sheet! I don’t count “off the decade” enough with my class. Thank you for the reminder and suggestions!

Halle

Across the Hall in 2nd Grade

My pleasure, Halle! Thanks for pinning it…isn’t Pinterest the best?

PS: I pinned your ws!