How to Use This Calculator
Click buttons or use your keyboard to enter numbers and operations. The expression you're building shows up above, and the answer appears when you calculate. Order of operations happens automatically—2 + 3 × 4 gives you 14, not 20.
Trig functions and logarithms work by entering your number first, then clicking the function button. Take sine of 30°—enter 30, click sin, and you'll get 0.5. Cosine, tangent, log, and ln work the same way—enter your number first. Powers like 2³ need you to enter 2, click xy, enter 3, then hit equals. ANS recalls your last result. Useful for chaining calculations.
Parentheses let you control order: (2+3)×4 forces the addition first. The DEG/RAD toggle switches between degrees and radians for trig functions—degrees is the default, unless you're doing calculus. Memory buttons store intermediate results: M+ adds to memory, MR recalls it, and MC clears it out. Type 80 × 25% to get 20.
What Is a Scientific Calculator?
A basic calculator handles addition, subtraction, multiplication, and division. That's it. A scientific calculator adds trig functions, logarithms, exponentials, roots, and a bunch of other operations you'll need for any math beyond basic arithmetic—especially in science and engineering classes. Physics problems throw angles and vectors at you constantly, chemistry uses logs for pH and exponentials for decay rates, and these calculators include the math functions you'll actually use in science courses. They're required for standardized tests like the SAT, ACT, and AP exams.
Graphing calculators (like the TI-84) go further by plotting graphs and solving equations, but they're not allowed on all tests. Financial calculators exist for business calculations but use completely different functions. This is a full-featured scientific calculator—it handles the standard set of functions without graphing features. For everyday math like adding receipts or figuring tips, a basic calculator works fine. But once you hit algebra, trig, or any science course, you'll need these extra buttons.
Trigonometric Functions
Sine measures the ratio between the opposite side and hypotenuse in a right triangle. On the unit circle, it gives you the y-coordinate. For a 30° angle, sin(30°) equals exactly 0.5. Cosine uses the adjacent side and hypotenuse—or the x-coordinate on the unit circle—and cos(60°) also equals 0.5. Tangent is the ratio of opposite to adjacent, sin divided by cos. Since tan(45°) equals 1, it's a good sanity check. Tangent is undefined at 90° and 270° because cosine hits zero there.
The inverse functions (asin, acos, atan) flip the question around. Instead of "what's the sine of 30°?" you're asking "what angle has a sine of 0.5?" The answer is 30°. These inverse functions only accept inputs between -1 and 1 for sine and cosine (because those are the only possible output values). Your calculator returns an angle in whichever mode you've selected—degrees or radians.
Degrees are what most people know: a full circle is 360°, a right angle is 90°. Radians are the "natural" unit for angles in calculus and physics, where a full circle is 2π radians (about 6.28). So π radians equals 180°, and π/2 equals 90°. Converting between them is simple—multiply degrees by π/180 to get radians, or multiply radians by 180/π to get degrees. Make sure you're in the right mode before doing trig—sin(30) in degree mode gives 0.5, but in radian mode it gives -0.988. Huge difference. If you know sin(30°) = 0.5, you can catch if you're in the wrong angle mode.
Some values to remember: sin(30°) = 0.5, sin(45°) ≈ 0.707, sin(60°) ≈ 0.866, and sin(90°) = 1. For cosine, cos(0°) = 1, cos(45°) ≈ 0.707, cos(60°) = 0.5, and cos(90°) = 0.
Logarithms and Exponentials
Logarithms flip the exponent question around. Instead of asking "what's 10²?" you ask "what power of 10 gives me 100?" The answer is 2, so log₁₀(100) = 2. The log button assumes base 10, used by scientists for pH, decibels, and the Richter scale. The ln button gives you the natural logarithm with base e (approximately 2.71828), showing up everywhere in calculus, continuous growth problems, and exponential decay. Logarithms are the inverse of exponentials, so they "undo" them. If 10³ = 1000, then log(1000) = 3.
The exponential buttons work the opposite way. The ex button raises e to whatever power you enter—so e² gives you about 7.389. The 10x button does the same thing with base 10. These are the inverse operations of ln and log respectively. Enter your exponent first, then hit the button. Some useful log rules: log(a×b) = log(a) + log(b), and log(aⁿ) = n×log(a). These help when you're solving exponential equations.
pH calculations use -log[H⁺] to measure acidity—if hydrogen ion concentration is 0.001, pH equals 3 (acidic). Decibels measure sound intensity on a log scale: dB = 10×log(I/I₀). The Richter scale for earthquakes uses logarithms of amplitude—each whole number jump means 10 times more energy. Half-life problems in chemistry need ln and exponentials to figure out decay rates.
Order of Operations
Order of operations follows PEMDAS: parentheses first, then exponents, then multiplication and division from left to right, finally addition and subtraction. That's why 2 + 3 × 4 equals 14—multiplication happens before addition. Take 8 ÷ 2 × 4 for example—it equals 16, not 1. You work left to right for operations at the same level. Same deal with 10 - 3 + 2, giving you 9 because you go left to right: (10 - 3) + 2 = 7 + 2 = 9. Don't do 10 - (3 + 2).
Use parentheses when you're unsure about order. Add extra parentheses if needed. Extra parentheses clarify your intent and prevent errors. Nested parentheses like ((2 + 3) × 4) - 1 work like you'd think—start with the innermost parentheses, so (5 × 4) - 1 = 20 - 1 = 19.
The problem 6 ÷ 2(1+2) confuses people because the notation is ambiguous—some read it as (6÷2)×3 = 9, others as 6÷(2×3) = 1. Use parentheses to clarify. When typing fractions, remember that 1/2x means (1/2)×x to most calculators, not 1/(2x). Add parentheses: 1/(2×x). If you want to square a negative number, type (-3)² to get 9, not -3² giving -9 because the negative is applied after squaring.
Special Functions
Factorial (n!) multiplies all positive integers from 1 to n. So 5! equals 5 × 4 × 3 × 2 × 1, which is 120. Press the n! button after entering your number. Factorials grow fast. By 10! you're over 3.6 million. Calculate 20! and you're at 2.4 quintillion. Your calculator will overflow somewhere around 170!. Factorials show up in probability, permutations, and combinations. "How many ways can you arrange 5 items?" That's 5! = 120 ways.
Absolute value |x| gives you the distance from zero, always positive. So |-5| = 5 and |5| = 5. You'll use it for distances and magnitudes. The reciprocal button (1/x) flips your number—reciprocal of 4 is 0.25. Faster than typing 1 ÷ x. Comes up in rate conversions and electrical resistance. Can't take the reciprocal of zero because 1/0 is undefined.
The percentage button converts to a decimal and continues your calculation. Type 80 × 25% and you'll get 20. Behind the scenes it's doing 80 × 0.25, but the % button handles the conversion. The mod button gives you remainders after division—17 mod 5 equals 2 because 17 ÷ 5 is 3 with remainder 2. Modulo shows up in clock arithmetic (15 o'clock = 15 mod 12 = 3 PM), checking divisibility, and computer science problems.
Memory Functions
Memory stores one number you can recall later—useful when you need to juggle multiple calculations. Most calculators have one memory register. MC clears the memory (sets it to zero) before starting a new problem. MR recalls whatever's stored there without changing it. M+ adds your current result to whatever's already in memory, and M- subtracts from it. These are handy for accumulating totals across multiple calculations.
Example: To calculate (15 × 4) + (20 ÷ 2) + (8²), clear memory with MC, then calculate each part and press M+ after each. Do 15 × 4 = 60 and press M+. Then 20 ÷ 2 = 10 and press M+ again. Finally 8² = 64 and press M+ once more. Press MR and you'll get 134. Beats writing down three numbers and adding them by hand.
Calculator Tips and Common Mistakes
Check the DEG/RAD indicator before trig calculations. Wrong mode means wrong answer. If you're calculating 47 × 23, do a quick mental estimate first: 50 × 20 = 1,000, so your answer should be somewhere near that. If it shows 10,000, you mistyped. These checks catch mistakes. Don't type 3.14159 repeatedly—use the π button. Same goes for e. Hit AC to clear the previous calculation before starting a new problem.
Your calculator does exactly what you tell it—if the result looks wrong, double-check your input. Typing too fast is a common problem. Fast clicking can cause missed inputs. Check the display before calculating. Don't forget to close your parentheses—(2+3×4 instead of (2+3)×4 will either auto-close (giving you a wrong answer) or throw an error. Trying to divide by zero gives an error. Make sure your denominators aren't zero before you calculate.
When You'll Actually Use This
In algebra classes, you'll use it for solving quadratic equations and handling exponents. Trigonometry courses are where the sin, cos, and tan buttons really shine—solving triangles, finding angles, converting coordinates. Calculus relies heavily on logarithms and exponentials for derivatives and integrals. Statistics courses need it for standard deviations and z-scores, though you'll probably want a specialized stats calculator if you're going deep into that subject.
Angles show up constantly in physics problems. Projectile motion breaks velocity into components using sin and cos, wave problems need trig for oscillations and log for decibels, while thermodynamics uses natural logarithms for entropy calculations. Chemistry work involves pH calculations (just -log[H⁺]), equilibrium constants (more logs), and radioactive decay problems using exponentials and natural logs.
All engineering disciplines rely on these functions—electrical work needs them for impedance and Bode plots, mechanical engineers use them for stress calculations, and civil engineers apply them in surveying.
The SAT and ACT allow scientific calculators (but not graphing ones). Having one speeds up calculations considerably, especially on the trig and exponential problems. AP exams for Calculus, Physics, and Chemistry all allow scientific calculators. The GRE and GMAT provide on-screen calculators, but they're basic—if you know how to use a scientific calculator efficiently, those tests get easier. Engineering licensing exams (FE and PE) allow approved calculators, so get comfortable with whichever model you plan to bring.