The Beatles hit No. 1 for the first time in America, tragedy strikes space shuttle Columbia, and Janet Jackson suffers a Super Bowl "wardrobe malfunction," all on this day.
30 / 48
Seth Morabito/Wikimedia Commons
1972: The first scientific hand-held calculator is introduced for $395 by Hewlett-Packard, named the HP-35 for having 35 keys. It was the first hand-held calculator able to perform logarithmic and trigonometric functions with one keystroke. The price was reduced several times, eventually to $195. By February 1975, when production of the model was discontinued, 300,000 of the calculators had been sold.