diff --git a/src/main/c/Calculator/calculator.c b/src/main/c/Calculator/calculator.c
index 13c4174..4f4ea4d 100644
--- a/src/main/c/Calculator/calculator.c
+++ b/src/main/c/Calculator/calculator.c
@@ -31,6 +31,16 @@ double combination(int n, int r);
                 num1 = n;
                 num2 = r;
             }
+                 if (choice != 4 || (choice == 4 && num2 != 0)) {
+                result = performOperation(choice, num1, num2);
+                printf("Result: %.2lf\n", result);
+            } else {
+                printf("Error: Division by zero\n");
+            }
+        } else if (choice != 20) {
+            printf("Invalid choice\n");
+        }
+    }
                   
         while (choice != 20);