body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
background-color: #f8f9fa;
color: #333;
line-height: 1.6;
margin: 0;
padding: 20px;
}
.loan-calc-container {
max-width: 700px;
margin: 30px auto;
background-color: #ffffff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}
h1, h2 {
color: #004a99;
text-align: center;
margin-bottom: 20px;
}
.input-group {
margin-bottom: 20px;
display: flex;
align-items: center;
flex-wrap: wrap; /* Allow wrapping for smaller screens */
}
.input-group label {
flex: 1 1 150px; /* Flex properties for label */
margin-right: 15px;
font-weight: bold;
color: #004a99;
text-align: right; /* Align labels to the right */
}
.input-group input[type="number"] {
flex: 2 1 200px; /* Flex properties for input */
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box; /* Include padding and border in the element's total width and height */
}
.button-group {
text-align: center;
margin-top: 30px;
}
button {
background-color: #004a99;
color: white;
border: none;
padding: 12px 25px;
border-radius: 5px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
}
button:hover {
background-color: #003366;
}
#result {
margin-top: 30px;
padding: 20px;
background-color: #e7f3ff;
border-left: 5px solid #28a745;
border-radius: 5px;
text-align: center;
}
#result h2 {
margin-bottom: 10px;
color: #004a99;
}
#result-value {
font-size: 2.5rem;
font-weight: bold;
color: #28a745;
}
.article-section {
margin-top: 40px;
padding-top: 20px;
border-top: 1px solid #eee;
}
.article-section h2 {
text-align: left;
color: #004a99;
}
.article-section p, .article-section ul {
margin-bottom: 15px;
}
.article-section li {
margin-bottom: 8px;
}
/* Responsive adjustments */
@media (max-width: 768px) {
.input-group {
flex-direction: column;
align-items: stretch;
}
.input-group label {
text-align: left;
margin-right: 0;
margin-bottom: 5px;
}
.input-group input[type="number"] {
width: 100%;
}
.loan-calc-container {
padding: 20px;
}
}
Understanding Simple Addition
Addition is one of the most fundamental arithmetic operations. It is the process of combining two or more numbers, known as addends or summands, to produce a single number, called the sum. In essence, it's about finding the total quantity when several quantities are brought together.
The symbol used for addition is '+'. For example, 5 + 3 = 8, where 5 and 3 are the addends, and 8 is the sum.
How the Calculator Works
This calculator takes up to four numbers as input. It prompts the user to enter values for each number field. The "First Number" and "Second Number" fields are mandatory, while the "Third Number" and "Fourth Number" fields are optional.
When you click the "Calculate Sum" button, the JavaScript code behind the calculator performs the following steps:
- It retrieves the values entered into the four input fields.
- It converts these values from text strings (which is how they are initially read from the input fields) into numbers.
- It checks if the mandatory fields ("First Number" and "Second Number") contain valid numbers. If not, it will display an error or default to 0 for those fields. Optional fields that are left blank are treated as 0.
- It adds all the valid numerical inputs together.
- Finally, it displays the calculated total sum in the designated result area.
Mathematical Principle
The core mathematical principle is the associative and commutative property of addition. This means that the order in which you add numbers does not change the sum (commutative), and the way numbers are grouped in addition does not affect the result (associative). The formula can be represented as:
Sum = Number 1 + Number 2 + Number 3 + Number 4
Where Number 3 and Number 4 are included only if they have valid numerical input.
Use Cases
While seemingly simple, basic addition is crucial in countless scenarios:
- Budgeting: Adding up expenses for different categories to understand total spending.
- Inventory Management: Summing up quantities of items in stock.
- Project Management: Calculating the total hours spent by a team on a task.
- Personal Finance: Adding up savings from different sources.
- Data Analysis: Aggregating data points to find totals.
- Everyday Calculations: Quickly adding up grocery items at the store, calculating distances, or combining measurements.
This calculator provides a straightforward tool for performing these basic aggregations quickly and accurately.
function calculateSum() {
var num1 = parseFloat(document.getElementById("number1").value);
var num2 = parseFloat(document.getElementById("number2").value);
var num3 = parseFloat(document.getElementById("number3").value);
var num4 = parseFloat(document.getElementById("number4").value);
// Check if inputs are valid numbers, default to 0 if not or if empty
if (isNaN(num1)) {
num1 = 0;
// Optional: provide user feedback for invalid input if needed
// alert("Please enter a valid number for the First Number.");
}
if (isNaN(num2)) {
num2 = 0;
// alert("Please enter a valid number for the Second Number.");
}
if (isNaN(num3)) {
num3 = 0; // Treat empty or invalid as 0 for optional fields
}
if (isNaN(num4)) {
num4 = 0; // Treat empty or invalid as 0 for optional fields
}
var totalSum = num1 + num2 + num3 + num4;
document.getElementById("result-value").innerText = totalSum;
}