Enter min ==> 1

Enter max ==> 100.0
Enter float number  
87.2
verified number is 87.2
grade is: B
Enter next number -9
Enter another score ==> 9
verified number is 9
grade is: F
Enter next number 100.5
Enter another score ==> 100
verified number is 100
grade is: A
Enter next number 79.9
verified number is 79.9
grade is: C
Enter next number 0