Commented the code a bit

average_biggest.c

@@ -1,5 +1,9 @@
 #include <stdio.h>
 
+/* A program to calculate the average of a set of numbers and the biggest
+ * of those numbers. From the book "Vägen till C". Translated it to english.
+ */
+
 int main()
 {
     float nr, sum, biggest;
@@ -9,13 +13,13 @@ int main()
     ant = 0;
 
     printf("Write the numbers.\n");
-    printf("Finish with EOF.\n");
+    printf("Finish with EOF.\n"); // EOF is CTRL-D in Unix/Linux
-    while (scanf("%f", &nr) == 1)
+    while (scanf("%f", &nr) == 1) // As long as we get characters to scanf, it's
-    {
+    {                             // true, ie '1'.
         ant++;
-        sum += nr;
+        sum += nr;                // Same as sum = sum + nr.
-        if (nr > biggest)
+        if (nr > biggest)         // If 'nr' is bigger than 'biggest', make 'nr'
-        {
+        {                         // the new 'biggest' value.
             biggest = nr;
         }
     }

avg_with_function.c

@@ -1,6 +1,10 @@
 #include <stdio.h>
 
-float max(float x, float y)
+/* A first example from the book "Vägen till C" where we get to use functions.
+ * Here is a function to get the biggest number from a set of numbers.
+ */
+
+float max(float x, float y) // It's return value is a float.
 {
     if (x > y)
     {
@@ -12,7 +16,7 @@ float max(float x, float y)
     }
 }
 
-int main()
+int main() // main's return value is an int (return 0 at the bottom).
 {
     float number, sum, biggest;
     int ant;
@@ -26,7 +30,7 @@ int main()
     {
         ant++;
         sum += number;
-        biggest = max(biggest, number);
+        biggest = max(biggest, number); // biggest goes into x, number into y.
     }
 
     printf("Average:    %.2f\n", sum / ant);

interest1.c

@@ -1,5 +1,7 @@
 #include <stdio.h>
-#define YEARS 10
+#define YEARS 15
+
+/* Simple example of a program to calculate interest on interest */
 
 int main()
 {
@@ -7,7 +9,7 @@ int main()
     int year;
     printf("Invested capial: "); scanf("%f", &cap);
     printf("Interest? "); scanf("%f", &interest);
-    printf("\n Year     Holding\n ====      =======\n");
+    printf("\n Year      Holding\n ====      =======\n");
 
     for (year = 1; year <= YEARS; year++)
     {

interest3.c

@@ -1,5 +1,10 @@
 #include <stdio.h>
 
+/* A simple program from the book "Vägen till C" to calculate for how long your
+ * money will have to sit in the bank at a given interest rate to reach the
+ * amount of money you'll want
+ */
+
 int main()
 {
     float cap, want, interest;
@@ -11,6 +16,9 @@ int main()
     
     year = 0;
 
+    /* As long as your capital at the bank is less than you want, keep rerunning
+     * the loop until we reach the amout we want. Each loop is one year.
+     */ 
     while (cap < want)
     {
         year = year + 1;