calculator class added

src/Calculator.java

+public class Calculator {
+
+
+        // Method to add two numbers
+        public int add(int a, int b) {
+            return a + b;
+        }
+
+        // Method to subtract two numbers
+        public int subtract(int a, int b) {
+            return a - b;
+        }
+
+        // Method to multiply two numbers
+        public int multiply(int a, int b) {
+            return a * b;
+        }
+
+        // Method to divide two numbers
+        public int divide(int a, int b) {
+            if (b == 0) {
+                throw new IllegalArgumentException("Cannot divide by zero");
+            }
+            return a / b;
+        }
+
+}