diff --git a/math/sum_of_digits.cpp b/math/sum_of_digits.cpp
new file mode 100644
index 000000000..d5a705c48
--- /dev/null
+++ b/math/sum_of_digits.cpp
@@ -0,0 +1,72 @@
+/**
+ * Copyright 2020 @author iamnambiar
+ * 
+ * @file
+ * \brief A C++ Program to find the Sum of Digits of input integer.
+ */
+#include <iostream>
+#include <cassert>
+
+/**
+ * Function to find the sum of the digits of an integer.
+ * @param num The integer.
+ * @return Sum of the digits of the integer.
+ * 
+ * \detail
+ * First the algorithm check whether the num is negative or positive,
+ * if it is negative, then we neglect the negative sign.
+ * Next, the algorithm extract the last digit of num by dividing by 10 
+ * and extracting the remainder and this is added to the sum.
+ * The number is then divided by 10 to remove the last digit.
+ * This loop continues until num becomes 0. 
+ */
+int sum_of_digits(int num) {
+    // If num is negative then negative sign is neglected.
+    if (num < 0) {
+        num = -1 * num;
+    }
+    int sum = 0;
+    while (num > 0) {
+        sum = sum + (num % 10);
+        num = num / 10;
+    }
+    return sum;
+}
+
+/**
+ * Function for testing the sum_of_digits() function with a
+ * first test case of 119765 and assert statement.
+ */
+void test1() {
+    int test_case_1 = sum_of_digits(119765);
+    assert(test_case_1 == 29);
+}
+
+/**
+ * Function for testing the sum_of_digits() function with a
+ * second test case of -12256 and assert statement.
+ */
+void test2() {
+    int test_case_2 = sum_of_digits(-12256);
+    assert(test_case_2 == 16);
+}
+
+/**
+ * Function for testing the sum_of_digits() with 
+ * all the test cases.
+ */
+void test() {
+    // First test.
+    test1();
+    // Second test.
+    test2();
+}
+
+/**
+ * Main Function
+*/
+int main() {
+    test();
+    std::cout << "Success." << std::endl;
+    return 0;
+}