Consul' the Educated Monkey. A mathematical toy calculator patented by William Robertson in 1916 and made by the Educational Novelty Company of Dayton, Ohio, USA. When each of the monkey's feet are moved to point at two numbers, the monkey's hands m
A single surface glass vessel made by Alan Bennett in Bedford, 1995. It consists of three Klein bottles sharing an inlet tube which when cut produces three pairs of single-twist Mobius strips. A Klein bottle is a surface which has no edges, no outsid
Single surface models made by Alan Bennett in Bedford, 1995. Three toroid single surface vessels, one with the loop inside the torus, one with a narrow loop outside and one with a wider loop outside. All can be cut to produce a pair of single-twist M
Calculating Rule 'Parker's Prestometer Tablet', c.1860 by Isaac Aston, London. One side of the rule is inscribed with multiplication tables involving halves.the other side has more complicated scales involving areas and volumes.
Twist & Shout Multiplication' a digital and audio mathematical toy by Leap Frog, a division of Knowledge Kids Enterprises. Complete with packaging, instructions and marked as manufactured in China, c.2000. This toy employs all the latest technology
Laundry tally board, English, of wood, brass and horn
`Baby Calculator' stylus adding device by Glenview, Illinois, USA, c. 1960. Like the Exactus, this is one of a number of simple stylus machines introduced in the mid 20th century. It performs multiplication and division by repeated addition and subtr
Mechanical ready reckoner patented by Patented by James Hines. This form of calculator gave costs of various quantities of goods at various prices per pound, hundredweight or ton. The quantity was set by turning the apropriate wheel at the side, and
A Klein bottle is a surface which has no edges, no outside or inside.
Twelve replica German jetons, originals date from the 16th century. These small counters were placed on a counting cloth in a similar manner to beads on an abacus.