How it works
Typing a sum
Press the keys or type on your keyboard: digits, + − * / ^, brackets, p for π, Enter for = and Escape to clear. Pasted text goes straight into the expression.
Where two values meet, a times sign goes in for you, so 2π reads as 2×π and 3sin(30) as 3×sin(30). Brackets you leave open are drawn faint and closed when you press =.
While you type, the value so far shows under the expression in grey. After =, an operator carries the answer on, and a digit starts a new sum.
Angles, logs and roots
In degrees, sin, cos and tan take degrees and asin, acos and atan give degrees back; radians work as they do in code. Results within a trillionth of 0, ±0.5 or ±1 are snapped to that value, so sin(30) is exactly 0.5.
log is base 10 and ln is the natural log. The ʸ√x key takes the index first, then the value, separated by a comma: root(3, −8) is −2, since odd roots of negative numbers are real.
ʸ√x = x^(1/y)
Precision and history
Answers show ten significant figures, and switch to ×10 notation past 10¹⁵ or below 10⁻¹⁰. Ans and an answer carried on keep their full double precision, so 1 ÷ 3 × 3 comes back as 1.
The last twenty sums stay in the history. Select one to edit it again, or use its result in the sum you are typing. Constants from mathematics, physics and chemistry go in with one click, at CODATA 2018 values.
