1976 · Low-Cost Scientific Calculator · Work 950 of 1,871
A classroom in a comprehensive school in England on a grey winter morning, a pupil in a dark blue school jumper seen from directly behind, face turned fully away, bent over a wooden desk, on it a wedge-shaped calculator of black plastic fifteen centimetres long, at its top a deep red window with a soft red glow, below a plain black strip and a plain smooth cream-beige key plate with rows of small black rectangular keys, every key plain smooth and unmarked, one fingertip on a key, an exercise book open flat at a page of fine squared grid, a yellow pencil, further pupils from behind ahead, tall windows on the left.
What it was used for
Texas Instruments launched the TI-30 scientific calculator in 1976 at 24.95 US dollars and built it until 1986. It has some 40 keys, an 8-digit LED display, reciprocal, square and square root, sine, cosine, tangent, logarithms, powers, pi, percent, parentheses and memory functions; the back reads "ASSEMBLED IN USA". It was aimed at teaching: TI advertised it for the classroom and issued a "TI-30 Student Math Kit" with a 224-page activity book. In 1975 the National Advisory Committee on Mathematical Education had recommended allowing calculators from grade eight in class and in examinations; in 1980 the recommendation was extended to all grades.
What was new
What marked the TI-30 was not an operation but a price point. It was considered basically the same as TI's own SR-40 - and that cost 49.95 dollars, a difference Datamath puts down to materials and battery. Trigonometry and logarithms could thus be had for 24.95 dollars, a year after a national advisory committee had recommended calculators for classwork and examinations. EdTech Magazine, citing Datamath, reports a reputed 15 million units sold between 1976 and 1983; Ball and Flamm in 1997 call the machine "probably the largest selling calculator of all time". The barb: a cheap scientific calculator probably became the best-selling one, at half the price of TI's own SR-40.
What the sources leave open: Price, keys, display and the Ball and Flamm quotation come from the Smithsonian object page (a 1977 example). The figure of 15 million units originates with Datamath and is repeated here only as EdTech Magazine repeats it: as a second-hand figure. datamath.org itself could not be retrieved in this run for technical reasons.