Ask the user to input a lower case letter, print a message like "Please enter a small case letter: " then convert it to upper case. If the letter is an uppercase letter, then give a message that "You entered an upper case letter. Enter again". Keep waiting for the user to input letter using a loop.

Critical thinking: getchar() works with buffered input. When you input a letter for example, 'a', then press Enter, the input buffer has two characters: 'a ', where ' ' is new line. You need to only print 'A'. You should clean the standard input stream once you have done your getchar call.

Write a farenheit to celsius converting program, celsius = (5/9)*(fahr- 32), output the following table:

200 93.33 190 87.78 180 82.22 170 76.67 160 71.11 150 65.56 140 60.00 130 54.44 120 48.89 110 43.33 100 37.78 90 32.22 80 26.67 70 21.11 60 15.56 50 10.00 40 4.44 30 -1.11 20 -6.67 10 -12.22 0 -17.78