Why does Math.random() method print only one value even though it is random?

Why does this code print only one value? I expected it to be random.

import java.util.Random;

public class abcd {
public static void main(String[] args){

int küme[] = new int[20];                       //creation of array

for(int i=0; i<20; i++){
    int number=(int) Math.random()*6;           // creation of random numbers between 0 and 5
    küme[i] = number;                           // assignment of random numbers
    System.out.print(" "+küme[i]);
  }
 }
}