Firstly , we are here to help others . If we do not help them , we can be silent , and leave no comment.
Secondly , I know the traditional way of multiplying , it is just one line of code ; But as I mentioned I am not allowed ti use package.
Thirdly , I know the material , I have implemented several operators without using package , and have done a lot of search . Every body prefers to choose easy way , and use '*' operator , like you.
Fourthly , unsigned multiplying is a trivial part of a bigger project . I have 5 more projects , I have to work on them ,and do not have enough time .