Added book examples

C4/simple_claculation.c

@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <stdlib.h>
+int main(void)
+{
+    int a = 6,b = 7,c; // Declare and initialiase as required
+    c = a + b;         // Add the values and store in c
+
+}