Elementary Mathematics printable file for the operations/number box - it includes almost everything you need, including fractions and parentheses, for the first few chapters of the Keys of the Universe Montessori mentoring mathematics album. This box is used throughout the album in various portions. 

The numbers box starts in chapter 2 and continues throughout most of the elementary Montessori Mathematics album. 

Color ink not required.  

You will want the following: 
--1 sheet of gray paper (cardstock) - Just so you know, I used light blue instead; no reason other than the contrast. 
--3 sheets of white paper (cardstock)
--black paper or black foam sheet (to cut fraction strips and make black hole punches)
--A tacklebox or other storage/display


Regardless of the tacklebox used, you want one with curved bottoms - the cards slip out SO much easier - and are less likely to slide under the dividers (though they will sometimes still do that - so you make sure they are in snug and/or add something - some people use some glue to seal the dividers down; or you can add a piece of felt along the entire bottom; or another idea).