methods2.java

import java.util.Scanner;
public class number2 {
    public static void main(String[] args) {

        Scanner input = new Scanner (System.in);

        double mark;

        System.out.println("Mark obtained: ");
        mark = input.nextDouble();

        grade(mark);
    }

    public static void grade(double mark) {
        if(mark >= 90) {
            System.out.println("A");
        }
        else
            if(mark >= 80 && mark <= 89) {
                System.out.println("B");
            }
            else
                if(mark >= 70 && mark <= 79) {
                    System.out.println("C");
                }
                else
                    if(mark >= 60 && mark <= 69) {
                        System.out.println("D");
                    }
                    else
                        if(mark < 60) {
                            System.out.println("F");
                        }
    }
}