How to multiply decimal numbers without using multiplication(*) sign

Question

Can anyone suggest me a way to multiply decimal numbers without using multiplication(*) sign. I know it looks like homework thing, but I just want to know how to achieve this. I have already done this for positive and negative integers as below:

int first = 2;
int second =2;
int result = 0;
bool isNegative = false;

if (first < 0)
{
    first = Math.Abs(first);
    isNegative = true;
}
if (second < 0)
{
    second = Math.Abs(second);
    isNegative = true;
}

for (int i = 1; i <= second; i++)
{
    result += first;
}

if (isNegative)
    result = -Math.Abs(result);

Want to multiply this for decimals:

decimal third = 1.1;
decimal fourth = 1.2;

Thanks

Answer 1

Bit of a cheat, but if the task strictly relates to all forms of multiplication (rather than just the * operator), then divide by the reciprocal:

var result = first / (1 / (decimal)second);

Answer 2

Just another way ;)

if (second < 0)
{ 
    second = Math.Abs(second);
    first = (-1) * first;
}
result = Enumerable.Repeat(first, second).Sum();