The level of numeracy in England was poor even among gentlemen, as shown by this ivory instrument. It gives the multiplication tables up to 10 with a...
The level of numeracy in England was poor even among gentlemen, as shown by this ivory instrument. It gives the multiplication tables up to 10 with a...
The level of numeracy in England was poor even among gentlemen, as shown by this ivory instrument. It gives the multiplication tables up to 10 with a...
The level of numeracy in England was poor even among gentlemen, as shown by this ivory instrument. It gives the multiplication tables up to 10 with a...
Invented by C L Chambon in 1880, the 'Tachypoly Plasiasme' ready reckoner showed multiplication tables up to 100 times 100.
Invented by C L Chambon, the 'Multiplicateur Enfantin' automatic calculator showed multiplication tables up to 50 times 28.
This abacus is of a type common in the 19th century. It is intended for use in base 16, with each bead above the bar being worth five units and each...