"In my opinion", "in my humble opinion"... Those are usual prefaces people tend to use to prevent the interlocutor about his/her total ignorance of a topic. Let me explain why...
They could use "I've no f*cking idea but I want to say something" and still have the same oratory effect.
Using that example from above it is quite simple to explain: BOTH ARE WRONG
"Why is this?" you may think (before giving "your humble opinion). Well, simple: SOMEONE wrote that number down and knows what is it. Perhaps there's a reference point like a building, or a context to deduct what is it (if it is a number at all) like a 5 and a 7 next to it or an 8 and a 10. That symbol, has a purpose that both people arguing about are total strangers to.
It is funny to observe, as I google for an image able to define "opinion" for this article, that 90% of them are all about "your opinion matters". A futile attempt to make people believe that knowing nothing about something but speaking anyways is something desired. Allow me to pop the bubble for you: It doesn't! And it isn't!
Opinion without information and judgement is worth as much as saying nothing (some may not risk a lot by stating that even shutting the F*ck up is worth more than giving "opinion" about a topic). Both characters in that example image are wrong because neither one of them is willing to ask someone that knows, or willing to observe the surroundings to deduct and theorize a potential, valid hypothesis.
For the sources of this post's images check THIS out.