Scarce Early 20th Century Milton Bradley Parish Number Tablets Set vintage ceramic lamp This made me laugh out

This made me laugh out loud when I found it

and I know from the seller that they were made in IK 19 prison in Kazan in 2010

with wear to the green paint on the interior bottom of the holder

7 1/4" x 6" x 2 3/4" t

9 3/8" t x 7 3/8" w x 1 3/4" d

Scarce Early 20th Century Milton Bradley Parish Number Tablets Set vintage ceramic lamp This made me laugh outI can find no other set of these out there anywhere, and pretty much no reference for them, except a few mentions of "number tablets" used for reaching simple math, produced on wood and cardboard in the later 19th and early 20th century, which is around when Milton Bradley produced these. Each of the 20 cards here is double sided (my photos show one side then the other of each, in batches.) I honestly do not know how they were used but certainly the