Math rounding in java

/**
 * @author lautturi.com
 * Java example: how to use math.round  math.floor
 */

import java.util.*;

public class Lautturi {

	public static void main(String[] args) {
		
		System.out.println(Math.floor(4.5));
		
		System.out.println(Math.floor(-5.4));
		System.out.println(Math.round(-5.4));
		
		System.out.println(Math.floor(-5.5));
		System.out.println(Math.round(-5.5));
		
		System.out.println(Math.floor(5.4));
		System.out.println(Math.floor(5.5));
		System.out.println(Math.round(5.5));
		
		System.out.println(Math.ceil(5.5));
		System.out.println(Math.floor(5.57 * 10) / 10);
		
	}
}

output:

4.0
-6.0
-5
-6.0
-5
5.0
5.0
6
6.0
5.5