After all, we did love playing a prank on him.
Answer - it has a dangling modifier which is a word or phrase that modifies a word not clearly stated in the sentence.
Reason - the sentence seems to suggest “I” gave birth to six puppies.
You can reread it as many times as needed to understand while listing to it the reader might not say a word right or skip parts
I would say it is probably common knowledge, because it isn't someone else's idea, but if you found it online or in an article you would probably want to credit any thoughts, ideas, or quotes. Be sure to state whose calculated this number also.
