Sometimes you just need to PAINT and CUT and DO even when you’re in 3rd grade. Yesterday was one of those days where I threw caution to the wind and decided we would spend some time painting and cutting and would *hopefully* have a fabulous math tool to show for our work and repurposing.

It is no secret I save trash, especially pieces of cardboard. Don’t EVER throw away cardboard labels. They are SO VERY USEFUL: canvas for painting, repairing paperback book covers, matting a picture, AND for making place value “blocks”!

First, my 3rd graders painted the back of the cardboard labels with various colors of craft paint. After allowing it to dry, we used rulers and a bic black ink pen to create the grids for hundred blocks and then cut some of those down for base tens and ones pieces.

My kiddos loved this! I did have to finish up some of the cutting and laminated it all, but in the process of making these, our 3rd graders also used their rulers to measure out the hundred blocks and base tens with 1/2-inch squares. Love it when an idea comes together! In the photo collage above and below, you can see the “front” of the original cardboard and that it is from our canvas bins from TarJay. Like I said, I NEVER throw away these kinds of cardboard pieces. They are super versatile and would cost you money to purchase in a store!

 Today, we used these repurposed math tools for some 3-digit addition and subtraction. I love it when light bulbs burn bright in learning, and that happened today as they more clearly understood why we “carry” and “borrow.” They used them with some of the cards from our Halloween Place Value resource as well today, just to make numbers with hundred blocks, base tens and one pieces.

Below are some photos from our actual lesson today. They were decomposing the base tens and the hundred blocks. The hundred block borrowing and carrying was a new concept for them.

After our lesson and some practice problems, they journaled in their math notebooks. My own sample is below in the first photo.

I’m linking up with Monday Made-It over at Fourth Grade Frolics! Hope your week is going well!

Please SHARE: What have you done lately with pieces of cardboard that you saved from the round file?