Stacking Number Blocks - Montessori Math Toy

Friends of 10 Toy Blocks

This is a set of Friends of 10 toy blocks designed as a simple, hands-on way to explore number relationships. Each block represents a number from 1 to 10, and when paired with its "friend," the sum equals 10. It’s a great way for kids to visualize addition and number bonds in a tactile way, making early math concepts easier to grasp.

UPDATE 2025-03-25: The V6 3mf files have been updated to include the correct NUMBER 7 with the base, just like the photos. It seems that in my hurry to set the scale of the objects more intentionally, I accidentally uploaded an old version of the number 7 block. This has been fixed in all print files, and the new raw .STL file for the V6 number 7 block has been added to the files.

UPDATE 2025-03-03: V5 Files have been updated such that the 10 is 155mm tall – this makes the math and checking the scale factors a bit easier while still keep the 100% scale quite large and easy to play with for small hands. All files have been updated to match this scale. If you are printing a new set, this does not affect you. If you are re-printing a number to match an old set (printed prior to March 03, 2025), you must scale by 99.63% on the X and Y axis, but leave the z-axis at 100%.

Added:

I've added an alternative model for the number 4 as it was a bit difficult to stack numbers on top of the original 4. Personally, I like the aesthetic of the original 4, but I do concede that this new version should stack much easier.

How to Use:

• Match pairs to make 10
• Mix and match to build basic equations
• Use as a stacking toy for open-ended play
• The height of the blocks indicates the sum of the numbers (5 stacked on top of 4 is equal to the height of the 9)

I've included print profiles for 100%, 75%, and 50% scales

100% Scale - Large Size for small hands.

75% Scale - MED size blocks. Save time and filament, still good size.

50% Scale - SMALL “pocket” sized print for older children.

NOTE--Smaller sized prints may be unsuitable for children under the age of 3. ESPECIALLY the 50% scale size print.

The infill is modified to create weight at the bottom of the blocks, making them more stable and less likely to tip over. This also helps them stack more easily.

The blocks are easy to print and don’t require supports. 

If you’re looking for an interactive way to reinforce early math skills, this set is a fun addition to any learning space.