Pascal makes device that performs all four arithmetic operations without humans. He succeeds but doesn’t mass produce the device and doesn’t patent it.
Thomas de Colmar patents and produces Arithmometer, a device that used sliders and cranks to add/subtract/multiply/divide.
Dorr. E. Felts makes the Comptometer, which had buttons
ENIAC filled a room, and weighed 27 tons, but did math completely electronically.
ANITA could do math and fitted on a table, used vacuum tubes to operate.
Programma 101 prints answers on paper and could even be programeed
ELKA 22 made in Bulgaria, could do square roots.
Texas Instruments makes groundbreaking “Cal Tech” prototype. It was handheld and printed answers onto paper.
Sharp QT-8B had fluorescent lights, microchips, and internal power.
TI 2550 was larger than earlier designs, but cheaper too.
Sharp’s EL-8026 had solar panels to provide power.
Casio fx-7000G was first ever graphing calculator.
TI-84 Plus (your graphing calculator) released.