Quintessential analog calculators still used sporadically in Asia. Two varieties: Chinese Suanpan, Japanese Soroban. Info
here. More here. Handbook here. Roman model here.

I learned how to use this device as a young boy. Lots of fun! Two rows of beads, five below and two above. Get a nice one
here on amazon. Find more info here.

Japanese abacus with four beads below and one above. Still used today to develop and facilitate incredible mental calculation feats. On amazon
here. Handbooks here and here.

Napier’s Bones and Genaille-Lucas Rulers
Ingenious calculation rods invented early in the 17th century by John Napier and improved by Henri Genaille in 1891. Make your own
here. Buy your own sets here , here, and here.

Pascal’s Calculator
Fascinating mechanical arithmetic calculating machine devised and patented in France by famous mathematician Blaise Pascal in the mid-17th century.

Mechanical Calculators
In centuries past, analog calculating machines were created out of necessity to improve speed and accuracy in arithmetic calculation. Mid-20th-century Addiator

Slide Rules
Colossal 20th century engineering feats owe their completion to the humble slide rule (e.g.
Golden Gate Bridge, early U.S. Space Program, etc.). User guides here and here.

Slide Rule Miscellany
There's a learning curve, and good
instruction is key. Collecting is a joy. Oughtred Society is famous. See model manuals here. Learn about the coveted Faber-Casell 2/83N,

Humans Calculators

Mental Calculators
Along with calculating machines, humans once did the bulk of arithmetic calculation. Adept
calculating professionals were tasked with this tedious, exacting, and essential work.

Mental Math
Affable professor Arthur Benjamin explains some of the tricks he uses to do crazy mental calculation miracles. See Dr. Benjamin's videos

Vedic Math
Modern Indian system of calculation. Speed and accuracy are famous features. See video by Indian wonder-kid Akash Vukoti
here. 1965 guidebook here.

First Modern Calculators

Early Electronic Calculators
Super-detailed article with vast amounts of info about early electronic calculators, including pictures and specifications for various models released during these years

The first pocket scientific calculator, released in 1972. Wildly popular but
expensive (originally $395; over $3,000 in 2023). The $25 Ti-30 came out four years later.

Casio CFX-200 Module 197
A beautiful, oddball,
highly-collectible scientific calculator watch produced by Casio in the early 1980s. Tiny keys. I had one of these, but accidentally drowned it.


Ada Lovelace
Mathematician and daughter of Lord Byron. Worked extensively with Charles Babbage's "Analytical Engine," Lovelace is widely regarded as the world's
first computer programmer.

History of Calculation
Article exploring analog calculation and calculators from ancient days until now. A great first read for those with a real interest in the subject.