[user02@FC4 Lesson06]$ cat -n mathvars.c

   1  #include <stdio.h>
   2
   3  int main(void)
   4  {
   5     float cost = 15.50;         // The cost of an item
   6     float sales_tax = 0.06;     // Sales tax is 6 percent
   7     float amount_paid = 20.00;  // The amount the buyer paid
   8     float tax, change, total;   // Sales tax, buyer change and
   9                                 // total bill
  10
  11     tax = cost * sales_tax;
  12     total = cost + tax;
  13     change = amount_paid - total;
  14
  15     printf("Item Cost: $%f\tTax: $%f\tTotal: $%f\n", cost, tax, total);
  16     printf("Customer change: $%f\n", change);
  17
  18     return 0;
  19  }

[user02@FC4 Lesson06]$ gcc -o mathvars mathvars.c
[user02@FC4 Lesson06]$ ./mathvars
Item Cost: $15.500000 Tax: $0.930000 Total: $16.430000
Customer change: $3.570000

---

[user02@FC4 Lesson06]$ cat -n mathvars2.c

   1  #include <stdio.h>
   2
   3  int main(void)
   4  {
   5     float cost = 15.50;         // The cost of an item
   6     float sales_tax = 0.06;     // Sales tax is 6 percent
   7     float amount_paid = 20.00;  // The amount the buyer paid
   8     float tax, change, total;   // Sales tax, buyer change and
   9                                 // total bill
  10
  11     tax = cost * sales_tax;
  12     total = cost + tax;
  13     change = amount_paid - total;
  14
  15     printf("Item Cost: $%.2f\tTax: $%.2f\tTotal: $%.2f\n", cost, tax, total);
  16     printf("Customer change: $%.2f\n", change);
  17
  18     return 0;
  19  }

[user02@FC4 Lesson06]$ gcc -o mathvars2 mathvars2.c
[user02@FC4 Lesson06]$ ./mathvars2
Item Cost: $15.50 Tax: $0.93 Total: $16.43
Customer change: $3.57