I'm not too sure what the multiplication principle is, but does it refer to cross-mutiplying?
Sorry if I misunderstood the question.
My name is Paul and I'm in class 5...sorry 'cuz I posted in this thread but...something is entangling me...sorry if I'm writing wrong 'cuz I'm from Romania...I don't know if this is harmonize with the thread but...1x2x3x...x20...how to resolve???
If can someone help me