Scientific Calculator
Trigonometry, logarithms, powers and factorials in one on-screen keypad, with degree and radian modes.
Factorial works for whole numbers from 0 to 170.
What is it
A scientific calculator adds the toolkit of math beyond arithmetic: trigonometric functions, logarithms, powers, factorials and the constants pi and e. Binary operations like × ÷ xʸ run in immediate-execution mode (same as the basic calculator), while unary keys like sin, ln or √ act on the number on screen right away. Toggle Deg/Rad to interpret angles.
Notes & fun facts
The π and e buttons on your calculator are literally engraved history: π has been pinned down to trillions of digits, while e (about 2.718) was discovered by Jacob Bernoulli around 1683 while asking what happens if your bank compounds interest continuously. The factorial key is a shortcut for counting permutations: 5! = 120 ways to line up five books.
Origin & history
The pocket scientific calculator arrived in 1968 with the Hewlett-Packard 9100A, and the legendary HP-35 in 1972 fit one into a shirt pocket, using Reverse Polish Notation. Trigonometry itself goes back to Hipparchus of Nicaea around 140 BC, who built the first chord tables. Logarithms were invented by John Napier in 1614, and factorial notation by Christian Kramp in 1808.