I want my kids (who are just learning numbers) to have something to help make math fun, and easy to grasp. Keeping it simple I also integrated a few design elements for compact and neat storage.

Updated!
Version 2:

• Redesigned the pieces
• Storage compartment bigger
• Better hinges
• STL to "print in-place" for hinges
• Clasp to hold it together
• Title "Intro to MATH" on the left side
• Cleaned the tolerances so less plastic removal after print (if any)

EDIT: Zip file contains the individual pieces 1 through 9. Included a Pieces Set # 1 - Perfect starting quantity, ready for printing.

Enjoy!