Sandpaper Numbers: Unveiling The Magic of Montessori Math

If you’re looking for an easy way to make your DIY authentic Montessori sandpaper numbers at home, look no further. Sandpaper numbers are an important part of the Montessori mathematic curriculum, and I’ll admit… these (and the sandpaper letters) were the most intimidating project to start making. However, after making this printable and DIY’ing the entire set, I promise you it’s much easier than you might think! Don’t get me wrong, this project IS time-consuming, but it is easy and totally worth it in the end.

Why should I DIY the sandpaper numbers and not buy them pre-made?
I contemplated for nearly a year on whether or not I wanted to take on this project. Purchasing the number set online would be a lot easier, and I could probably get away with spending under $100. But that’s the thing about the Montessori method… every major learning activity/tool can cost up to $50 (or more!). That adds up fast. So, picking and choosing which items to make vs. buy is an important task when you’re trying to do Montessori home school on a budget. Ultimately, I decided that making them myself meant they would be easily replaceable, repairable, re-makeable, and durable enough for little hands. Use the DIY tools & materials you already have on hand (see my post 8 Must-Have Montessori Home school Materials and Tools) and have these awesome cards ready for your child’s first language art lessons.

Why sandpaper numbers?

Maria Montessori came up with the concept of sandpaper numbers and letters at the first school she opened. The school happened to be in a poverty-stricken neighborhood in Rome, where mothers and fathers were leaving their children as young as 2 or 3 years old to wander the neighborhood while they went off to work (I KNOW… CRAZY!). The school was named Casa dei Bambini (or “Children’s House”). She had the difficult task of figuring out how to teach reading and writing not just letters, but also numbers, to these children. She believed that from the age of 4 or 5, a child could (and would) burst into reading and writing spontaneously – if they were taught in conjunction with one another. By using a tactile surface like sandpaper, the children were able to trace the number with their fingers, recite the name of the number, and prepare themselves for reading, writing and mathematics at the same time. This process also creates a mind-body connection, helping with their comprehension. To make these numbers she used very simple materials and simply cut the numbers out of sandpaper and glued them to square pieces of cardboard.

The tutorial I have put together for you here is just as simple, but a bit of a modernized take on her original method of creation. I highly recommend taking the additional steps to ensure durability if you are trying to use these for more than one child.

These printables and cards are also directly inspired by the authentic NAMC homeschool curriculum I mentioned in my post about the first 3 years of Montessori homeschooling.

About The Printable
Below you’ll find one printable for the sandpaper numbers, 0-9. Click the download now button and the PDF will download to your computer, or click the link and it will open in a new tab.

Shopping List

Green Cardstock (Astrobright Green Cardstock )
Printer
X-Acto Knife (Basic X-Acto Knife with Extra Blades )
Scissors
Cutting Mat (Basic Craft Cutting Mat)

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Sandpaper Number Printable

FREE – Sandpaper Numbers Download

Learn how to make your own Montessori Sandpaper Numbers for mathematics. Download the free printable template and follow the steps below.

Approx. 12 Hours

Print Out the Sandpaper Number Printable

Above these steps, you’ll find a printable for the numbers. Print the numbers on Yellow cardstock, and the blank rectangles on the green cardstock. Double-check that your printer is set to the right paper setting for cardstock. Set the pages that contain the numbers aside for the moment (images for the instructions are for the letters so please disregard the paper coloring from the images).
Cut the Blank Rectangles

Next, cut the blank rectangles from the green cardstock using a paper cutter or sharp scissors. You will end up with 11 blank green rectangles (enough for each number 0-10). Don’t worry too much if your lines aren’t perfectly straight or some of the black ink from the printer shows on the edges. Once you are done laminating and trimming the cards, you won’t even notice, and I promise you… your child won’t notice or care either! This project is time-consuming enough- so don’t obsess over perfection.
Laminate the Blank Rectangles

I wanted to stay true to authentic Montessori cards, and that meant keeping the size recommendations given by the NAMC homeschool curriculum I have. Because of the size, each lamination sheet will hold 2 blank rectangles. Once you are finished laminating all of the blank rectangles (2 per lamination sheet), cut them out from the lamination sheets. I always run them through the laminator a second time after I have cut them out to make sure the edges are bonded well, but that step is completely optional. It only takes a few extra minutes to do it and from my experience, it does help with durability.
Cut the Numbers from the Cardstock

Now that you’ve finished laminating the blank rectangles, it’s time to start the process of making the actual sandpaper numbers. Lay out your cutting mat (highly recommend using a cutting mat, but some good thick pieces of cardboard can be used in a pinch). Place one of the number pages on the cutting mat and carefully cut out the black number using an X-Acto knife. TIPS (From Firsthand Experience…If you don’t have much experience using an X-Acto knife, do not worry. Here are a few tips that should help you get a good start:
-Don’t stress about perfection! These will be glued to sandpaper and don’t need to be perfect. If you cut through a number, save both pieces. They are meant to be used as a guide for cutting the sandpaper.
-Use a fresh blade in the X-Acto knife and replace the blade the second it seems to be getting dull.
-For numbers with spaces in the middle (8,0, etc.), cut the inner region out before cutting the outer edge.
– Hold your X-Acto knife with a nice grip just as you would hold a pen during writing and cut towards yourself
-Rotate the paper on curved edges a little bit at a time as you cut the curve
-Use a ruler to cut along the straight edges by placing the X-Acto knife alongside the ruler to keep it straight
Glue the Numbers to the Back of the Sandpaper Backwards

After you have cut each letter from the cardstock it’s time to glue them to the back of the sandpaper. I tried a variety of glues to test which one would be the best for this project and found that gorilla glue’s permanent adhesive dried clear and didn’t seep through the sandpaper. Of course, you can use any kind of permanent glue you’d like but do NOT use super glue. It will leave an ugly watermark under the sandpaper you won’t be proud of. When you glue the numbers to the back of the sandpaper, be sure to glue them backwards. Put the glue on the black ink side of the number and then adhere it to the sandpaper. You can use something heavy, like books or weight, to keep the sandpaper flat while it dries. Once they are very dry (usually after 24 hours) you’re ready to move on to the next step.
Cut the Numbers from the Sandpaper

After the numbers are dried to the sandpaper, cut the letters out again using a combination of the X-Acto knife and a sharp pair of scissors. I found that for some numbers using the scissors was easier, while other numbers were best cut using an X-Acto knife. Use your best judgment and remember to change out your blade if it’s getting dull. Take your time, but don’t be too picky. Children won’t notice a slanted line or a bit of unevenness when they use these cards. When you’re done, you will have the numbers 0-10 in sandpaper. You’re almost finished!
Glue the Sandpaper Numbers to the Laminated Cards

The numbers you cut out in step 4 were off-center on the rectangle cards, and this is on purpose. This is how traditional Montessori sandpaper numbers are constructed. When gluing your numbers to the laminated rectangles, refer back to the printable to see approximately where it should be glued to the card. Make sure that your laminated card is in the landscape position and glue the sandpaper numbers to the laminated rectangle cards. Use a weight, book, etc., for a few minutes to flatten the number on the card and let the letters dry completely for 24 hours.