ca. 1920-1930s]. Green metal tin, 20.5 cm in diametre, 1.2cm in depth, containing within two pairs of revolving discs riveted in place, the upper made of printed green metal with a printed card disc below, the upper discs with 9 cut out windows and eight columns of numbers alongside a corresponding pin-holes; some foxing and soiling evident to card discs; with instructions printed on tin base; without the original stylus for turning the discs though still functional; tin somewhat soiled and scuffed, but otherwise a good and scarce survivor. A scarce and ‘delightful’ educational game ‘for speedily learning the facts of arithmetic’, produced by the Educational Device Company of Medina in New York. One of a series of ‘drill-tests now ‘ready’, the present example includes discs to help students with the manual calculation for ‘column addition’ and ‘part of numbers - Fractions’. ‘Work the problem at one of the windows. The answer to this problem is in the column to the right. Put the stylus in the hole beside the answer you think is the correct one, and push the upper disc as far to the left as it will go. There - if you have selected the correct answer, the stylus will drop into a hole in the lower disc. Keep the stylus firmly in this hole, and pull both discs as far to the right as the stop will permit. This will bring a new problem to the window. Work it as above, and keep on indefinately until all the facts are learned’. (Instructions).
We are unsure as to whether the discs were intended to be interchangeable: the rivets seem to be immovable so perhaps not, but the instructions note that others were available, however, dealing addition, subtraction, multiplication, and division.
Far from ‘delightful’, the game appears rather devilish (though may perhaps not be revolving as fully intended). Google provides some tantalising snippets of contemporary reviews, which seem to suggest it was well reviewed in its day. ‘A very clever piece of work’ and ‘marvellous little machine’ according to the American Educational Digest: The School Executives Magazine of 1923 and 1924, that ‘simply won’t allow the child to make a single mistake. Think of it - every example done correctly and no papers to correct! It seems uncanny but it is true’ (Normal Instructor and Teachers World, vol 34). Surviving examples appear to be extremely scarce, however, with a possibly earlier variant existing that was housed within a wooden box. We have for far been unable to find any further information about Kuhn.