We’ve been having some fun exploring the sensorial decanomial the last couple of weeks. Both kids have been working on this – neither one has seen it before and Meatball will start working on the elementary version very soon so I wanted her to have the sensorial experience first.

At the sensorial level this is about visual discrimination of size. Students begin by laying out the smallest red square. After that, the children create 9 more layers. Each layer consists of one square and various rectangles, creating a new overall square.

We worked through the sequence laid out in the Montessori Print Shop Sensorial Manual. First we compared just the squares in each color, seeing that each square’s size changes in the same proportion to all the others.

On another day we laid out the whole decanomial. I laid out the first couple of layers, then the girls took turns with the following colors.

On another day we took one color of the decanomial and ordered the rectangles from largest to smallest.

On yet another day we built binomials from the rectangles. Cheeseball recognized the pattern and grabbed the binomial cube to compare.

This, of course, is indirect preparation for work with multiplication tables and squares. I admit, it was very hard not to pepper this information in – Meatball is ready for it but we’re just filling in a couple of other holes first. However, I managed to keep quiet, and I know it’ll be worth it when she makes the connection very soon.

My decanomial square is simply made from cardstock. I made a quick .svg file and cut the file on my Cricut. Yes, this could be done with a paper cutter, but the Cricut makes for perfect, error free shapes. If you’d like to make your own decanomial, you can grab the file from my store.

Now to scrounge around the house and see if we have enough beads for the elementary version…