People's best friend has always been and will always be the calculator, not dogs.
This powerful yet small instrument has undergone a few big facelifts over the millennia, but their essential operations would have been familiar to our forefathers.
More powerful mechanical forms would evolve from the simple Abacus until they took numerous quantum jumps in power with the introduction of the first electronics and finally the microprocessor. Their ultimate and most significant improvement was the removal of their physical shackles, allowing them to become virtually entirely virtual on an unimaginable number of computers and smart gadgets.
The physical complexity of calculators peaked in the 1990s, but the emergence of the internet, personal computers, and, eventually, smartphones rendered them mostly obsolete.
Ancient times - In ancient times, the abacus was the primary tool for computation.
BC100 - Greek Antikythera Mechanism (BC100).
1500 - Leonardo da Vinci invented the first mechanical calculator around 1500.
1600 - John Napier invents "Napier's bones" for multiplication, based on the old numerical method known as the Arabian lattice.
1620 - William Gunter created a logarithmic method for multiplication and division using dividers in 1620, which was the predecessor to the slide rule.
1622 - William Oughtred devised the circular slide rule in 1622 and documented the rectilinear variant in 1633. 1642 - Blaise Pascal began work on the Pascaline, a mechanical calculator, in 1642. Capable of addition, subtraction was accomplished by nines-complement addition, and multiplication was accomplished through repeated additions and subtractions. It had flaws and failed to sell.
1673 - In 1673, Gottfried Leibniz created the first calculator capable of multiplication and division. He made the Stepped Reckoner out of stepped gear wheels. Performed the four responsibilities, although in an unorthodox manner due to a fault in the carry mechanism; none were sold
1820 - The Arithmometer of Charles Xavier Thomas, 1820.
1822 - Charles Babbage created the first Difference Engine in 1822.
1850 - Victor Mayer Amedee Mannheim standardized the current slide rule in 1850.
1853 - The Scheutz Difference Engine, the world's first printing calculator, is constructed in 1853.
1874 - W.T. Odhner, a Swedish engineer, designed the Odhner calculator in 1874, which is based on the pin-wheel idea. Many calculating machines have utilized the same approach since then (eg. Odhner).
1878 - Ramon de Verea created the first direct multiplication machine in 1878. This is far faster than transferring carriage or other digital approaches.
1884 - Dorr E. Felt creates the Comptometer, the first successful key-driven adding and calculating machine, in 1884. In 1886, he formed the Felt & Tarrant Manufacturing Company with Robert Tarrant.
1890 - Charpentier manufactures a calculator in 1890.
1891 - William S. Burroughs launched commercial production of his printing adding calculator in 1891.
1890 - Millionaire calculators are first launched in 1899. It supported direct multiplication by any digit - "one crank spin for each figure in the multiplier."
1902 - The Dalton adding-listing machine was the first of its kind to employ only ten keys - the first ten-key add-lister.
1947 - Curta's small hand-held mechanical calculator is introduced in 1947.
1960 - Bell Punch/Sumlock is the first electronic desktop calculator. Anita Mk VII is a cold-cathode vacuum tube-based amplifier. Orange discharge tube displays are employed.
1964 - The Friden EC130 and EC132, as well as the IME 84 and Sharp Compet, are the first all-transistor desk calculators (Prices comparable to that of family cars).
1969 - Casio AL-1000 Four-Function Programmable Calculator (Weight 12.3 kg).
Sharp QT-8D, with Rockwell ICs, was the first calculator to use just LSI (Large Scale Integration) chips. The calculator's size and weight have been greatly decreased, and it is now portable.
1970 - Facit 1123 - 14 digits with nixie tubes, 4 functions, and memory.
1972 - Bowmar 901B Electronic Calculator, Made in the USA, 1972.
1972 - Hewlett-Packard HP 35, the first scientific pocket calculator, is introduced. HP Calculator Heritage Page.
If you need an example of the rising pace of technological progress, go no farther than the electronic calculator, that humble little instrument that instantly performs the most complex sums and fits in the palm of your hand. Or, more likely, don't any longer... since the pocket calculator, which evolved over four millennia and only achieved its current form in the 1990s, is already outmoded, if not obsolete.