Scientific Calculator

How to use this scientific calculator

Start by entering a mathematical expression in the display, either with your keyboard or with the on-screen keys. For example, enter 2*sin(30)+5! and press the equals key. With the angle selector set to DEG, the calculator evaluates the sine of 30 degrees as 0.5, multiplies it by 2, then adds 120 from 5 factorial. The result is 121. You can also type expressions such as sqrt(81)+2^3, log(1000) or (18-6)/3.

The display follows standard mathematical precedence, so it evaluates powers before multiplication and performs addition or subtraction afterward. Add parentheses whenever the intended grouping might be unclear. Press 2nd to change the sin, cos and tan buttons into their inverse forms. History records completed calculations so you can check and reuse an earlier expression, while Ans inserts the previous numerical result.

Scientific calculator functions and symbols

A scientific calculator extends ordinary addition and subtraction with functions used in algebra, geometry, science and statistics. The buttons are grouped so that common number keys remain easy to reach while advanced operations are close to the top. The following table shows what the main functions do and how to write them in the expression field.

Degrees vs radians: which mode should you use?

The DEG and RAD buttons control trigonometric angles. Degrees divide a complete circle into 360 parts. Radians measure angles using the circle’s radius, with one full turn equal to 2π radians. For school geometry questions written with a degree symbol, select DEG. For calculus, physics or expressions that contain π, radians may be more suitable.

Changing the angle unit does not change arithmetic such as 8+6 or logarithms such as log(100). It changes the meaning of inputs to sin, cos and tan, and the units of answers returned by inverse trig functions. If a trigonometry answer looks incorrect, check the mode before changing the values. Remember that tan(90) is undefined in degrees; the tool reports that case instead of giving a misleading enormous result caused by floating-point rounding.

How powers, roots and logarithms work

Use the power key for an exponent: 2^10 gives 1,024. A negative exponent represents a reciprocal, so 2^-3 gives 0.125. For roots, sqrt(49) returns 7, and cbrt(-8) returns -2. The general root function uses two inputs: root(3,27) asks for the cube root of 27. The root degree is written first and the number second.

Logarithms answer a different question: to what power must a base be raised to give a number? The common logarithm log uses base 10, so log(1000) is 3 because 10³ equals 1000. The natural logarithm ln uses the constant e, approximately 2.71828. Because logarithms of zero and negative numbers are not real-valued, the calculator displays an error for those inputs.

Factorials, combinations and permutations

The factorial operation multiplies every positive whole number from 1 through a chosen number. For example, 5! means 5 × 4 × 3 × 2 × 1, which equals 120. In this calculator, factorial is limited to whole numbers from 0 to 170, because larger results exceed ordinary JavaScript number limits. Negative numbers and decimal factorials are not supported.

Combinations and permutations are useful for counting possible selections. The expression nCr(5,2) counts the ways to choose two items from five when order does not matter; the result is 10. In contrast, nPr(5,2) counts arrangements where order matters, giving 20. Both require non-negative whole numbers, with the second input no larger than the first.

Memory keys, Ans and calculation history

The memory buttons are for calculations that build on each other. M+ adds the current expression’s value to memory, M− subtracts it, MR inserts the stored memory value and MC resets memory to zero. For example, calculate 12 × 4 and press M+; then calculate 8 × 5 and press M+. MR now represents 88. Memory is independent of the Ans key, which always refers to the last completed calculation.

The history panel shows up to 25 completed calculations and their results. Selecting an earlier entry restores its expression for editing, including the angle mode used originally. For privacy, the history is held only in the current page session and disappears when you reload. The calculator itself does not upload your mathematical inputs to a server.

Percentage, scientific notation and common mistakes

On this calculator, the percent symbol divides the number immediately before it by 100: 15% equals 0.15. For a percentage of a number, type 250*15% to get 37.5. The percent key does not automatically apply a discount to the preceding total in an expression such as 250−15%; for that purpose type 250*(1-15%), which gives 212.5. For more percentage-specific methods, use the dedicated Percentage Calculator.

The EXP button enters the exponent marker used in scientific notation. For example, 6.02E23 represents 6.02 × 10²³. Do not confuse E in a number with the mathematical constant e. The calculator also accepts implicit multiplication, so 2pi and 2sin(30) are interpreted as multiplication, but writing * explicitly makes complex expressions easier to read.

When handling very large or very small numbers, results may be displayed in scientific notation. This tool uses JavaScript double-precision arithmetic and shows roughly 13 significant digits, so results may be rounded. It does not support symbolic algebra, graphing, complex numbers or exact arbitrary-precision fractions. If a result is intended for a regulated scientific, engineering or financial decision, check it using an appropriate professional method.

Worked scientific calculator examples

Frequently asked questions

CalculatorForWork provides educational math tools. Verify critical numerical results and check applicable rounding rules before relying on a calculation.