Montessori Snake Games

What are all those snake games in Montessori !? Children are playing with SNAKES!?

Haha - well maybe they are! ;)

What follows is how AMI organizes the snake games - I would love to hear how other albums/trainings name them or organize them:

when it says gray with red binding - don't use red ;)
all the colors show up nicely on GRAY (even the gray!)
not so much on red - too distracting

Addition Snake Game

• first presented at the beginning of the addition memorization sequence, but then is to run concurrent with the addition strip board and memorization charts. The albums seem to make it look like it should be finished before starting those other works; nope - concurrent ;) Hm. Perhaps AMI albums could be more clear in stating this concurrency; that the snake game should be introduced but not completed. I'll go have a talk with myself on that one ;)  
• Materials: 3 boxes - One red box/lid with five colored bead stairs of 1-9 (total of 45 bead bars); one gold box/lid of 25 ten-bars; one white box ( black lid) with the black and white bead stair (beads 1-5 on each bar are black, 6-9 white); tray for the three boxes; small notched card (bridge) with its own container; piece of gray felt with red binding (32x18 inches)

Subtraction Snake Game

• first presented at the beginning of the subtraction memorization sequence, then runs concurrent with the subtraction strip board and memorization charts. The addition snake game should be mostly mastered before starting subtraction, but this can vary on the child.
• Materials: 4 boxes - One green box/lid of five colored bead stairs; one gold box of 25 ten-bars; one gray box with the gray bead stair (beads 1-5 on each bar are light gray, 6-9 dark gray); one black and white box with the black and white bead stair (beads 1-5 on each bar are black, 6-9 white); tray for the four boxes; small notched card (bridge) with its own container; piece of gray felt with green binding (32x18 inches)
• NOTE: If you are doing all one set and pulling just the boxes you need; the red box in addition IS the green box in subtraction (red for addition, green for subtraction). Use felt for this portion - or don't worry about it. The children in a homeschool setting don't need the cue as much as children in a school setting where they have a separate addition snake game from the subtraction snake game. OR if you have bought this set and have a white box with red lid for the red/white bead stair - you could use that for addition, then swap the colored bars to the green box for subtraction; since that red/white won't be used again until you are doing the full set-up, at which point the colored bead bars are in the green box anyway ;)

Elementary Negative Snake Game

• typically an early upper elementary work, but with interest or gifted children can certainly be done in lower elementary. Pre-requisites listed are "Knowledge of addition and subtraction facts; preparatory work with the ideas of negative numbers; addition and subtraction snake games in the primary class." Later notes in the album pages say "usually age 8". Thus interest or local educational standards are the driving forces here. 
• Materials: 6 boxes - colored bead bars, gray/white bead bars, golden ten bars, black/white bead stair, 25 gray ten bars, 1 red/white stair 

Some albums seem to list a middle-ground negative snake game; it is even mentioned in the elementary AMI math album because some children will come in with experience with it; but it is not found in the AMI albums. From what I can tell (please provide information in the comments if you know about this one!) it seems to be the Subtraction Snake Game with Negative Snake Game terminology added in. ???
The main difference: with the "real" Negative Snake Game, you can actually GET negative answers because you have the bead bars to do so.

And some people just call the Subtraction Snake Game a Negative Snake Game. It does the same thing, just is visually different, and doesn't get into the terminology of negatives. 

UPDATE 3/1/2014: For a second Montessori Nugget on Snake Games - including a note on the Multiplication Snake Game, please visit this Montessori Nugget.

UPDATE 1/22/2016: Adding the following somewhat more detailed pictures: 

All boxes for the Elementary Negative Snake Game
for 4-5 year old children, remove the unneeded ones

Addition Snake Game needs
3 boxes (contents listed above)

Subtraction Snake Game - same as the addition
adding the gray bars of 1-9 - 5 sets

Elementary Negative Snake Game - now we go to negative numbers
and need the red/white negative place holders and gray negative 10-bars. 

All boxes, opened, to show the tops with the bottoms (if you choose to go with bottoms in a homemade set)
If using tacklebox storage - good to have a felt bottom with the sides lined with the "lid color"