Im DROWNING! need help with a simple java assignment! plz someone help me!

Question

i need help with my java assignment, with validating a sin number. easy for must who know java. im drowning... please help!

Answer 1

You will need to store each digit of the social insurance number in a field of its own. To validate the entry you will:
1. Multiply the 2nd, 4th, 6th and 8th digit by 2.
2. If the product of any of the four multiplications result in a value greater than 9, add the two resulting digits together to yield a single-digit response. For example 6 * 2 = 12, so you would add the 1 and the 2 to get a result of 3.
3. Add these four calculated values together, along with the 1st, 3rd, 5th, and 7th digits of the original number.
4. Subtract this sum from the next highest multiple of 10.
5. The difference should be equal to the 9th digit, which is considered the check digit.
Example of validating S.I.N. 765932546
1st digit 7
2nd digit (6*2 =12 1+2=) 3
3rd digit 5
4th digit (9*2 = 18 1+8 =) 9
5th digit 3
6th digit (2*2 = 4) 4
7th digit 5
8th digit (4*2 = 8) 8
Total 44 next multiple of 10 is 50
50-44 = 6 which is the 9th digit
Therefore the S.I.N. 765932546 is Valid
********* SIN Validation *********
Welcome - Please enter the first number: 120406780
Second digit value multiplied by 2 4
Fourth digit value multiplied by 2 8
Sixth digit value multiplied by 2 12
Eighth digit value multiplied by 2 16
Value derived from 6th digit 3
Value derived from 8th digit 7
The total is 30
Calculated digit is 10
Check digit must be zero because calculated value is 10
The SIN 120406780 is Valid
this is my assignemtn this is what i have! i dont know where to start! please help me!
/*     File:     sinnumber.java
     Author:     Ashley
     Date:     October 2006
     Purpose: Lab1
import java.util.Scanner;
public class Lab1
          public static void main(String[] args)
               Scanner input = new Scanner(System.in);
               int sin = 0;
               int number0, number1, number2, number3, number4, number5, number6, number7, number8;
               int count = 0;
               int second, fourth, sixth, eighth;
               System.out.print("\t\n**********************************");
               System.out.print("\t\n**********SIN Validation**********");
               System.out.print("\t\n**********************************");
               System.out.println("\t\nPlease enter the First sin number: ");
               sin = input.nextInt();
               count = int.length(sin);     
               if (count > 8 || count < 8)
               System.out.print("Valid: ");
     }