Step 1 Define the start of the program 
 
It should be noted that within C all commands should end in a semi-colon. For most of your programs the definition of a program header as follows. The meanings of these commands are discussed later.
 
      include
      include
      include
      include
 
      void main()
      {
      char prompt;
 
        *******actual program code here ****
 
      printf("Press any key to exit \n\r");
      scanf("\n%c",&prompt);
      }
 
Step 2 Define the variables used 
 
  float number1;
 
Step 3 Inform the outside world that a number is required 
 
  printf(" Please enter in a value of number1 \n\r");
 
Step 4 Get the number 1 into the program
 
  scanf("%f ",&number1);
 
Step 5 Display the number 1 on the screen
 
  printf("The value of number 1 is %f \n\r",number1);
 
 
Actual program

  #include
  #include
  #include
  #include
 
void main()
  {
  char prompt;
  float number1;
  printf(" Please enter in a value of number1 \n\r");
  scanf("%f",&number1);
  printf("The value of number 1 is %f \n\r",number1);
  printf("Press any key to exit \n\r");
  scanf("\n%c",&prompt);
 
  }
  
The printf statement allows us to use formatted output i.e. specify the number of decimal places etc. The general syntax of the '%' format is 
 
    % flag  Field Size . precision argument size conversion . 
 
e.g    %+  forces printf to print a + and - sign for the variable
  %5   forces printf to reserve 5 spaces for the total variable including signs etc 
  %.3  forces printf to print 3 decimal points  rounded up .
 
   printf("The value of num1 is %+8.3f \n\r ",num1);
 
This prints out the contents of num1 in the format of signed value with a total space reserved of 6 digits (1 used for sign, 1 for decimal point). These 6 digits are further broken down in 3 integers and 3 decimal points.