Isn’t it 9, so how many birds are there?

Sorry for the confusion! My previous answer was probably based on an error in interpretation or in an image that we discussed together (perhaps in another thread).

Since I can’t see the specific picture or puzzle you’re encountering here at the moment, I can’t confirm the number of birds.

To solve it correctly:

• If you have a picture in front of you: Try to see if some birds are hiding in the leaves, shadows or if the bodies of two birds merge into one. Often in these puzzles, “bonus” birds are hidden in the contours of branches.
• As for the math puzzle: Please write me the exact wording.

Can you upload the picture for me or describe the riddle? I’ll be happy to look at it again and this time with more attention to detail!