Understanding the Casio MS-80B and Basic Arithmetic
The Casio MS-80B is a compact desktop calculator designed for everyday calculations. It features a large, easy-to-read display and standard arithmetic functions. While this emulation focuses on the core four operations (addition, subtraction, multiplication, and division), the actual MS-80B includes additional functions like percentage, square root, and memory operations.
Core Functions Emulated:
Addition (+): Combines two numbers. For example, 5 + 3 = 8.
Subtraction (-): Finds the difference between two numbers. For example, 10 – 4 = 6.
Multiplication (*): Repeated addition. For example, 4 * 3 = 12 (which is 4 + 4 + 4).
Division (/): Splits a number into equal parts. For example, 12 / 3 = 4.
How the Calculator Works (Logic):
This emulation captures the basic input and output mechanism of a simple calculator. When you enter a number, it appears on the display. When you press an operation button, the first number and the operation are stored. When you enter the second number and press the equals button (implicitly handled by the operation buttons in this simplified version for demonstration), the calculation is performed, and the result is displayed.
Mathematical Operations:
Addition: If you input a and b, the operation is a + b.
Subtraction: If you input a and b, the operation is a - b.
Multiplication: If you input a and b, the operation is a * b.
Division: If you input a and b, the operation is a / b. Special care is taken to prevent division by zero.
Use Cases for the Casio MS-80B:
The Casio MS-80B, and calculators like it, are invaluable tools for:
Students: For homework, tests, and quick calculations in math and science classes.
Office Professionals: For budgeting, expense tracking, sales calculations, and data entry.
Home Use: For managing household budgets, calculating bills, and everyday quick math.
Retail and Sales: For quick price checks, discounts, and transaction totals.
Example Calculation:
Let's say you want to calculate the total cost of 5 items at $12 each, plus a $5 shipping fee. While this emulator focuses on basic two-number operations, a real MS-80B could handle this sequentially:
Enter 5.
Press the multiplication button *.
Enter 12.
Press =. The display shows 60.
Press the addition button +.
Enter 5.
Press =. The display shows 65.
This demonstrates how sequential operations build upon previous results, a key feature of most basic calculators.
var currentValue = ";
var currentOperation = null;
var waitingForSecondOperand = false;
var firstOperand = null;
function updateDisplay(value) {
document.getElementById('display').innerText = value;
}
function handleNumberInput(num) {
if (waitingForSecondOperand) {
currentValue = num;
waitingForSecondOperand = false;
} else {
currentValue = currentValue ? currentValue + num : num;
}
updateDisplay(currentValue);
}
function performOperation(operator) {
var input1Value = document.getElementById('input1').value;
var input2Value = document.getElementById('input2').value;
var resultElement = document.getElementById('result');
if (input1Value === " || input2Value === ") {
resultElement.innerText = "Please enter both values";
return;
}
var num1 = parseFloat(input1Value);
var num2 = parseFloat(input2Value);
if (isNaN(num1) || isNaN(num2)) {
resultElement.innerText = "Invalid input";
return;
}
var calculationResult = ";
switch (operator) {
case '+':
calculationResult = num1 + num2;
break;
case '-':
calculationResult = num1 – num2;
break;
case '*':
calculationResult = num1 * num2;
break;
case '/':
if (num2 === 0) {
resultElement.innerText = "Cannot divide by zero";
return;
}
calculationResult = num1 / num2;
break;
default:
return;
}
resultElement.innerText = "Result: " + calculationResult;
// Optionally update display with result if simulating calculator flow
// updateDisplay(calculationResult.toString());
}
function clearDisplay() {
currentValue = ";
currentOperation = null;
waitingForSecondOperand = false;
firstOperand = null;
updateDisplay('0');
document.getElementById('input1').value = ";
document.getElementById('input2').value = ";
document.getElementById('result').innerText = 'Result';
}
// Simplified backspace for the direct input fields
function backspace() {
var input1 = document.getElementById('input1');
var input2 = document.getElementById('input2');
var resultElement = document.getElementById('result');
// Prioritize deleting from input2 if it has focus or is being typed into
if (input2.value && input2.value.length > 0) {
input2.value = input2.value.slice(0, -1);
resultElement.innerText = 'Result'; // Reset result on manual input change
} else if (input1.value && input1.value.length > 0) {
input1.value = input1.value.slice(0, -1);
resultElement.innerText = 'Result'; // Reset result on manual input change
} else {
// If both are empty, clear the display (simulating backspace on display)
currentValue = ";
updateDisplay('0');
}
// If backspacing clears an input, ensure result is reset
if (input1.value === " && input2.value === ") {
resultElement.innerText = 'Result';
}
}
// Initial display setup
updateDisplay('0');