HP 21S Stat/Math Calculator from 1989

This video is about the HP 21S, a niche statistics and maths calculator from HP's Pioneer series. Sections of this video: 0:00 - Intro 1:22 - Physical Design 3:21 - Basic Usage 4:46 - Probability Distribution Functions 8:23 - Statistics and Welford's Method 10:27 - Built-in Library 11:30 - Summary For those that are interested in knowing more about how to disassemble an HP 20S or HP 21S check out Logan West's video here:    • HP 20s Calculator Screen/Keyboard Repair   For those that are interested in Welford's Method for calculating the mean and variance of normal distributions check out this link: https://jonisalonen.com/2013/deriving... For more calculator videos check out my channel:    / calculatorculture