Error in BCD multiplication

Question

My method is supposed to take two BCDs, which are ints constructed from a driver, and multiply them together:

public BCD multiplyBCDs(BCD other){ //to multiply two BCDs together
    BCD basebcd = new BCD(digit);
    BCD otherbasebcd = other;
    int base = 0;
    for(int y = 0; y<basebcd.numberOfDigits();y++){
        base += digit[y];
        int g = y;
        while(g < basebcd.numberOfDigits()){
            digit[g]*=10;
            g++;
        }
    }
    int baser = 0;
    if(otherbasebcd.numberOfDigits() >= basebcd.numberOfDigits()){
        for(int v = 0; v < otherbasebcd.numberOfDigits(); v++){
            baser += base*otherbasebcd.nthDigit(v);
            int j = v;
            while(j < other.numberOfDigits()){
                byten(otherbasebcd.nthDigit(j));
                j++;
            }
        }
    }
    else{
        for(int v = 0; v < basebcd.numberOfDigits(); v++){
            baser += base*otherbasebcd.nthDigit(v);
            int j = v;
            while(j < other.numberOfDigits()){
                byten(otherbasebcd.nthDigit(j));
                j++;
            }
        }
    }
    BCD newBCD = new BCD(baser);
    return newBCD;
}

the byten method is supposed to multiply "other" by 10 for each digit, resulting in a number like 838 instead of 8+3+8. But If I put in the numbers 10 and 12, the the method will add 10*1 and 10*2, which comes out to be 30 instead of 120. Any suggestions?

byten:

public int byten(int j){
    j*=10;
    return j;
}

Answer 1

Change the input to integers

int a= Integer.parseInt(basebcd.toString(), 2);
int b = Integer.parseInt(otherbasebcd.toString(), 2);

Do operation with the two ints

res = i*j;

Convert to BCD

String s = Integer.toBinaryString(res);