Scientific Calculator 991 Plus

Scientific Calculator 991 Plus works like the scientific calculator on your school desk, with the textbook display you know: fractions, roots, powers, integrals and π look exactly as they do in your book, and answers stay exact.

√8 + √18 gives 5√2, not 7.0710678. 2/3 + 1/4 gives 11/12. Press S⇔D whenever you want the decimal.

★ TEXTBOOK DISPLAY
• Fractions, mixed numbers, roots, powers, logs and absolute values typed as you write them
• Exact answers with surds, fractions and π; S⇔D switches to decimal
• Recurring decimals turn back into fractions

★ 10 MODES IN ONE APP
• COMP – everyday and scientific calculation
• CMPLX – complex numbers in a+bi and polar form, conjugate, argument
• STAT – one-variable statistics and 7 regressions with data tables
• BASE-N – decimal, hex, binary, octal and logic operations
• EQN – quadratic and cubic equations with exact roots, plus 2 and 3 unknowns
• MATRIX – up to 3×3: determinant, inverse, transpose, products
• TABLE – a table of values for f(x) with start, end and step
• VECTOR – dot and cross product, angle and length
• DIST – normal, binomial and Poisson distributions
• INEQ – polynomial inequalities

★ CALCULUS AND MORE
• Integrals ∫, derivatives d/dx and sums Σ
• SOLVE and CALC with variables A–F, X, Y, M
• nPr, nCr, x!, Pol, Rec, random numbers and random integers
• 40 scientific constants and 40 unit conversions
• Degrees, radians and gradians; sexagesimal ° ′ ″
• Answer memory, history and replay: go back and edit any calculation

★ MADE FOR STUDENTS
• Familiar fx-991 style key layout with SHIFT and ALPHA functions
• Key guide: long-press any key to see what it does
• Report button: tell us if an answer ever looks wrong
• Works fully offline, no account, no permissions, no data collected

Good for school, high school, college and engineering maths: algebra, trigonometry, statistics, calculus and physics homework.

Scientific Calculator 991 Plus is an independent app. It is not affiliated with, endorsed by or connected to Casio Computer Co., Ltd. All product names are the property of their owners.

Questions or ideas: [email protected]