Hi there!
If any term, no matter what the number multiplied by zero will always turn out to be zero. I can give you an example of why this is correct.
We'll use apples. :P
If we have four apples multiplied by zero, you'd have zero apple because there's NO groups of apples to use.
Two times three is six because there are two groups of three, or three groups of two. But since earlier we said that there were zero groups of apples, there is zero groups of four so that cancels out to make none.
Hope this helps! :D