Calculator Key Guide

The Complete Reference for Calculator Button Functions

Understanding Calculator Keys and Their Functions

Welcome to the definitive guide on calculator keys and their functions. Whether you're using a basic calculator for everyday calculations or a scientific calculator for complex mathematical operations, understanding the purpose of each calculator key is essential for efficient and accurate calculations.

This comprehensive guide explains the most common calculator keys found on standard and scientific calculators, their functions, and how to use them effectively. From basic arithmetic operations to advanced scientific functions, we've got you covered.

Interactive calculator image - hover over keys to see their function

Basic Operation Calculator Keys

These fundamental calculator keys are present on virtually all calculators and are used for basic arithmetic operations.

+

Addition Key

The addition calculator key adds two numbers together. Example: 5 + 3 = 8

-

Subtraction Key

The subtraction calculator key subtracts the second number from the first. Example: 9 - 4 = 5

×

Multiplication Key

The multiplication calculator key multiplies two numbers together. Example: 6 × 7 = 42

÷

Division Key

The division calculator key divides the first number by the second. Example: 15 ÷ 3 = 5

=

Equals Key

The equals calculator key calculates and displays the result of the entered operation.

.

Decimal Point Key

The decimal point calculator key adds a decimal point to enter decimal numbers. Example: 3.14

AC

All Clear Key

The AC calculator key clears all entries and calculations, resetting the calculator to zero.

CE

Clear Entry Key

The CE calculator key clears only the most recent entry without affecting previous calculations.

Memory Operation Calculator Keys

Memory calculator keys allow you to store and recall values during calculations, making complex multi-step calculations easier.

M+

Memory Add Key

The M+ calculator key adds the displayed value to the value stored in memory.

M-

Memory Subtract Key

The M- calculator key subtracts the displayed value from the value stored in memory.

MR

Memory Recall Key

The MR calculator key displays the value currently stored in memory without changing it.

MC

Memory Clear Key

The MC calculator key clears the value stored in memory, setting it to zero.

MS

Memory Store Key

The MS calculator key stores the displayed value in memory, replacing any previous value.

Scientific Calculator Keys

Scientific calculator keys enable advanced mathematical operations for engineering, physics, mathematics, and other technical fields.

sin

Sine Key

The sine calculator key calculates the sine of an angle in degrees or radians.

cos

Cosine Key

The cosine calculator key calculates the cosine of an angle in degrees or radians.

tan

Tangent Key

The tangent calculator key calculates the tangent of an angle in degrees or radians.

log

Logarithm Key

The logarithm calculator key calculates the base-10 logarithm of a number.

ln

Natural Logarithm Key

The natural logarithm calculator key calculates the base-e logarithm of a number.

Square Key

The square calculator key calculates the square (second power) of a number.

Square Root Key

The square root calculator key calculates the square root of a positive number.

x^y

Power Key

The power calculator key raises a number to the power of another number.

Special Function Calculator Keys

Special function calculator keys provide additional capabilities for specific calculation needs.

%

Percentage Key

The percentage calculator key calculates percentages or converts a number to a percentage.

π

Pi Key

The pi calculator key inserts the mathematical constant π (approximately 3.14159).

e

Euler's Number Key

The e calculator key inserts the mathematical constant e (approximately 2.71828).

EXP

Exponent Key

The EXP calculator key allows entry of numbers in scientific notation (e.g., 3.5 × 10^6).

DEG/RAD

Degree/Radian Key

The DEG/RAD calculator key switches between degree and radian modes for trigonometric functions.

( )

Parentheses Keys

The parentheses calculator keys group operations to control the order of calculation.

1/x

Reciprocal Key

The reciprocal calculator key calculates the reciprocal (1 divided by the number).

+/-

Change Sign Key

The change sign calculator key changes the sign of the displayed number (positive to negative or vice versa).

Frequently Asked Questions About Calculator Keys

What is the difference between AC and CE calculator keys?

The AC (All Clear) calculator key resets the entire calculator, clearing all operations and memory. The CE (Clear Entry) key only clears the most recent entry, allowing you to correct a mistake without starting the entire calculation over.

How do memory calculator keys work?

Memory calculator keys (M+, M-, MR, MC, MS) allow you to store and manipulate values in the calculator's memory. This is useful for complex calculations where you need to use the same value multiple times or perform calculations with running totals.

What does the EXP calculator key do?

The EXP calculator key is used for scientific notation. It allows you to enter very large or very small numbers efficiently. For example, instead of typing 5,000,000, you can enter 5 EXP 6 (meaning 5 × 10^6).

Why do some calculators have both sin and sin⁻¹ keys?

The sin calculator key calculates the sine of an angle, while the sin⁻¹ (inverse sine or arcsine) key performs the opposite operation—it gives you the angle whose sine is the entered value.