Do you know the difference between a fact and an opinion? It can be a hard thing to understand. Some things are facts like the number of robots in this book. Other things are opinions like which robot would make the best friend, or which robot dances best. And sometimes to tell the difference between a fact and an opinion, you need to wait to get more information that s because facts can be proven true or false, and opinions are things you feel and believe but that you can t prove.