JavaScript provides various ways to work with numbers. Here are some common operations and use cases:

1. Basic Arithmetic Operations: You can perform basic arithmetic operations such as addition, subtraction, multiplication, and division.

   javascript
   let a = 5;
   let b = 3;
   
   let sum = a + b;
   let difference = a - b;
   let product = a * b;
   let quotient = a / b;
   

2. Increment and Decrement: JavaScript provides shorthand notations for incrementing and decrementing variables.

   javascript
   let counter = 0;
   
   counter++; // Increment by 1
   counter--; // Decrement by 1
   

3. Exponential Notation: You can use the exponentiation operator (**) for raising a number to a power.

   javascript
   let result = 2 ** 3; // 2 raised to the power of 3 (2^3)
   

4. Modulus Operator: The modulus operator (%) returns the remainder of a division operation.

   javascript
   let remainder = 10 % 3; // Result: 1 (remainder of 10 divided by 3)
   

5. Math Object: JavaScript provides a Math object with many built-in methods for more advanced mathematical operations.

   javascript
   let x = Math.sqrt(25);   // Square root
   let y = Math.random();   // Random number between 0 and 1
   let z = Math.floor(3.14); // Round down to the nearest integer
   

6. Conversion: You can convert strings to numbers using parseInt() or parseFloat().

   javascript
   let numString = "42";
   let num = parseInt(numString); // Converts to integer
   

7. Number Methods: Numbers in JavaScript are primitive values, but you can use methods on number literals by converting them to objects using the Number constructor.

   javascript
   let num = 123;
   let numObject = new Number(num);
   
   let decimalString = numObject.toFixed(2); // Rounds to 2 decimal places
   

8. NaN (Not a Number): You can use isNaN() to check if a value is not a number.

   javascript
   let value = "Hello";
   let isNotANumber = isNaN(value); // true
   

These are just a few examples of how you can use numbers in JavaScript. Depending on your specific needs, you may encounter various other scenarios where numbers play a crucial role.