[user02@FC4 Lesson08]$ cat -n showgrad.c

   1  #include <stdio.h>
   2
   3  int main(void)
   4  {
   5     int test_score;
   6
   7     printf("Type in your test score and press Enter: ");
   8     scanf("%d", &test_score);
   9
  10     if (test_score >= 90)
  11        printf("You got an A!\n");
  12     else if (test_score >= 80)
  13        printf("You got a B!\n");
  14     else if (test_score >= 70)
  15        printf("You got a C\n");
  16     else if (test_score >= 60)
  17        printf("Your grade was a D\n");
  18     else
  19        printf("You failed the test\n");
  20
  21     return 0;
  22  }

[user02@FC4 Lesson08]$ gcc -o showgrad showgrad.c
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: 100
You got an A!
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: 90
You got an A!
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: 89
You got a B!
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: 79
You got a C
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: 69
Your grade was a D
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: 59
You failed the test
[user02@FC4 Lesson08]$ ./showgrad
Type in your test score and press Enter: -20
You failed the test