1. Basic Arithmetic Keys

+ (Addition): Adds two numbers together.
- (Subtraction): Subtracts the second number from the first.
* (Multiplication): Multiplies two numbers.
/ (Division): Divides the first number by the second.
= (Equals): Calculates the result of the current operation.
C (Clear): Clears the current calculation.
CE (Clear Entry): Clears the last entered number.

2. Scientific Function Keys

sin (Sine): Calculates the sine of an angle.
cos (Cosine): Calculates the cosine of an angle.
tan (Tangent): Calculates the tangent of an angle.
log (Logarithm): Calculates base-10 logarithm.
ln (Natural Logarithm): Calculates natural logarithm (base e).
√ (Square Root): Calculates the square root of a number.
x² (Square): Squares the current number.
x^y (Power): Raises a number to a specified power.

3. Memory Function Keys

MS (Memory Store): Stores the current value in memory.
MR (Memory Recall): Recalls the value from memory.
M+ (Memory Add): Adds the current value to memory.
M- (Memory Subtract): Subtracts the current value from memory.
MC (Memory Clear): Clears the memory value.

4. Special Function Keys

± (Plus/Minus): Changes the sign of the current number.
% (Percentage): Calculates percentages.
1/x (Reciprocal): Calculates the reciprocal of a number.
π (Pi): Inserts the value of pi (3.14159...).
e (Euler's Number): Inserts the value of e (2.71828...).
! (Factorial): Calculates the factorial of a number.

5. Navigation Keys

← (Backspace): Deletes the last entered digit.
↑ (History Up): Navigates up through calculation history.
↓ (History Down): Navigates down through calculation history.
Enter: Same as equals (=) key in most calculators.