Electronic Pocket Calculator by Santek model ST-108 (8 digit / four function )
The electronic pocket calculator revolutionised personal computation, leading to the obsolescence of the slide rule by the mid 1970s. As with other avoiders of arithmetic, there were concerns that its use would lead to a decline in mathematical understanding. In the year this machine was made, 72% of maths teachers surveyed by the National Council of Mathematics Teachers in the USA opposed their introduction. This early Japanese machine could add, subtract, multiply, divide and calculate percentages.