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My eyes were first opened to the potential of unit blocks when I read this post on How We Montessori. I was intrigued so I requested Teaching Numeracy, Literacy, and Language with Blocks from our state library system. I highly recommend reading it if you are curious about unit blocks or wonder what the big deal is.
After your read the book you’ll definitely want to start of collection of blocks, but they are expensive. It’s important (IMO) to stick with true to size, actual unit blocks. You can add blocks from any source later on and they should still work well as long as they are standard sizes. A regular unit block is 1 3/8″ x 2 3/4″ x 5 1/2″.
I have been very happy with Barclay Blocks. Their prices are reasonable, not as high as some, and they have a large selection of open stock pieces so that you piece together your own set just the way you want it. They even provide a detailed set of instructions for making your own blocks right on their website. At the bottom of the instructions page their is a place to order lengths of block stock that are already the right dimensions and just need straight cuts to make them in to unit blocks, half units, columns, etc. It is MUCH cheaper to buy stock and do the cutting yourself.
I have done quite a bit of woodworking but I still had to do some research to understand exactly how they suggest cutting the blocks. You can use a table saw, a miter saw (though they warn against chipping), or a radial arm saw. The trick is, you need a way to accurately cut several blocks of the exact same length.
If you want to use a miter saw, I suggest the blade mentioned on the instructions page and a setup like this one to help with the repeat cuts.
I opted to build a crosscut sled for our table saw and buy the recommended blade. There are several tutorials on YouTube, just search “crosscut sled for miter saw”. It was hard to take the time to build something just to make something else, but I’m so glad I did. Now that I had the sled I can cut more blocks later and not have to worry about the accuracy.
Here’s a picture of my setup:
After being cut, each piece needs to be lightly sanded. It’s important not to round the corners too much; that would make the blocks tip easily. I put my palm sander in the vice and quickly ran the blocks over it. It took a lot longer than the cutting did.
If you can find a place that allows for neatly sorting and stacking the blocks it makes it easier to identify and locate the different pieces as needed. This really speaks to a child’s sense of order, much more so than a big tub of blocks thrown together. We keep ours in one side of our preschool cabinet for now.