feat: implement add, difference, multiplication and division functions

src/lib.cairo

@@ -1,27 +1,43 @@
 fn main() {
     short_str();
     let result = check_num(30);
-    println!("check_sum fn result here: {result}");
-    let sum: u16 = add_num(10, 5);
-    println!("the sum of 2 numbers is: {sum}");
+    println!("Check_sum function result here: {}", result); // Fixed the string interpolation syntax
+    let sum: u16 = add_num(20, 4);
+    println!("The sum is: {}", sum); // Fixed the string interpolation syntax
+    let diff: u16 = sub_num(12, 3);
+    println!("The difference is: {}", diff); // Fixed variable name mismatch in string interpolation
+    let mul_val: u16 = mul_num(4, 5);
+    println!("The product is {}", mul_val);
+    let div_val: u16 = div_num(12, 2);
+    println!("The result is {}", div_val);
 }
 
-// short string data type
+// Short string data type
 fn short_str() {
-    println!("GM Cairo!");
+    println!("Good morning, Cairo!");
 }
 
-// bool data type
+// Boolean data type
 fn check_num(n1: u8) -> bool {
-    if n1 > 20 {
-        return true;
-    }
-    return false;
+    n1 > 20 // Simplified boolean return
 }
 
-// function to perform basic addition arithmetic operation
+// Function to perform basic addition arithmetic operation
 fn add_num(n1: u16, n2: u16) -> u16 {
-    let result: u16 = n1 + n2;
-    return result;
+    n1 + n2 // Simplified return
 }
 
+// Function to perform basic subtraction arithmetic operation
+fn sub_num(n1: u16, n2: u16) -> u16 {
+    n1 - n2 // Simplified return
+}
+
+// Function to perform basic multiplication arithmetic operation
+fn mul_num(n1: u16, n2: u16) -> u16 {
+    n1 * n2 // Simplified return
+}
+
+// Function to perform basic division arithmetic operation
+fn div_num(n1: u16, n2: u16) -> u16 {
+    n1 / n2 // Corrected syntax and simplified return
+}