java How to convert a positive int to an array of digits?  using stream

Write a Java program to take an array of ints, print the number of 9's in that array.

Create a java code to find the average and standard deviation of a number in a array

Write a java program (class) called Grades to do the following. Must use an array. Ask the user for 20 grades. Get from the user each grade and fill an array with the grades. Find the average of the elements of the array. Print how many grades are smaller than the average. To get you started, your program code will begin as follows: import java. util. *; //includes Scanner public class Grades { public static void main(String[] args) { //begins main method