Jairus Calculator

Jairus Calculator puts a full scientific calculator on your iPhone. It's the Jairus Instruments JR-7: a solar-panel shell, a four-line display, glossy keys that press in. Turn the phone sideways and it becomes Jairus, a sheet where every line solves itself as you type.

THE JR-7 CALCULATOR (UPRIGHT) • Exact fractions: 1/2 + 1/3 = 5/6, not 0.8333. Mixed numbers, and ◂▸ to flip between fraction and decimal. • Four-line display: see your last two problems and answers above what you're typing. • Trig (degrees or radians), logs, powers, roots, factorials, nCr and nPr, and scientific notation. • Store values in x, y, z, t, a, b and c, and reuse your last answer with Ans. • 2nd functions printed right above each key, just like a handheld. • Keys register the instant you touch them, with a light tap you can feel. • Remembers your last 80 calculations, even after you close the app.

JAIRUS (SIDEWAYS) • One expression per line, with answers live as you type. • Define things and reuse them: a = 3, f(x) = x² + 1, f(a). • f′(3) gives the slope of f at 3. ans is the line above's answer. • Three keypads: main, abc and func, which covers csc/sec/cot, inverse and hyperbolic trig, floor, ceil, round, min, max, mod and more. • Undo and redo, and your lines are saved.

BETTER TOGETHER Your calculator's last answer is waiting as ans on the sheet's first line, and the sheet's answer comes back as Ans when you turn the phone upright.

No ads, no accounts, no tracking. Everything stays on your iPhone.

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