Free resources, further modifications to the LST
calculator .
Major changes:
1. Each time a mathematical symbol is entered, the user will be redirected to the numeric keypad page, enhancing input consistency.
2. Added logarithm calculation, including common logarithms, natural logarithms, and logarithms with arbitrary bases (log(argument/base) log(8/2) = 3, i.e., log₂8).
3. Added factorial
4. Can the QR code be added to jump to the current post?
Instructions for the calculator (AI-generated, human-proofread):
🔢 Basic Operations
Numbers and Symbols: Click 0–9, ., +, -, *, /, (,) to perform regular calculations.
Example: (5 + 3) * 2 = 16
Clear:
C: Clear all input
⌫ (Delete key): Deletes the last character.
Equals: Click = Calculation Result
⚙️ Exponentiation (power)
Use ** to represent exponentiation (JavaScript standard syntax)
Example:
2**3 → 8 (2 to the power of 3)
4**(1/2) → 2 (square root)
8**(-1) → 0.125 (reciprocal)
e**2 → ≈7.389
PI**2 → ≈9.8696
💡 Tip: Please enclose negative or fractional exponents in parentheses, such as 2*
(-3) or 27* (1/3).
➗ Modulo operation (%)
% represents the modulo operation, not a percentage!
Syntax: a % b → Returns the remainder when a is divided by b
Example:
10% 3 → 1
15% 4 → 3
7% 2 → 1
Note: The sign of the result should be the same as that of the dividend, e.g., -7 % 3 → -1
❌ Percentages are not supported (e.g., 50% will be treated as 50% [the next number], which usually leads to errors).
📐 Mathematical Functions (Click "More" to expand)
Button function input format example
√ Square root sqrt(x) sqrt(25) → 5
c. Cosine cos(x) cos(0) → 1
sine sin(x) sin(PI/2) → 1
t = tangent tan(x) tan(PI/4) → 1
x! factorial fact(x) fact(4) → 24
lg is the common logarithm (base 10): lg(x) lg(100) → 2
logarithm with any base: log(argument/base) log(8/2) → 3 (i.e. log₂8)
ln(natural logarithm, base e) ln(x) ln(e) → 1
⚠️ Note:
All functions require manual completion of the closing parenthesis, such as sin(PI/2).
The parameters of trigonometric functions are in radians (π radians = 180°).
Factorials only accept non-negative integers, in the range 0 ≤ n ≤ 170.
🔢 Constants
Π → Pi (≈3.1415926535)
e → natural constant e (≈2.7182818284)
Examples: e**PI, PI*e, cos(PI), etc. can all be used directly.
📌 Usage Tips
Nested calls: fact(sqrt(16)) → fact(4) → 24
Mixed expression: 2**3 + lg(1000) - 10%3 → 8 + 3 - 1 = 10
Exact square root: 16**(1/4) → 2 (fourth root)
Negative number handling: (-2)**3 → -8 (parentheses are required)
❌ Common Mistakes
Correct way to write the reason for incorrect input
log(8,2) does not support comma-separated log(8/2).
The expression sin 30 is missing parentheses sin(30) (and 30 is in radians!).
50% alone % meaningless % must be between two numbers, such as 100% 7