Whats 9 + 10. My younger sister (whos obsessed with texting) asked me whats 9 + 10. I say 19, and she laughs. shes been held back multiple times, so I seriously don't know if shes joking about that 21 meme, or really simply stupid

Tell her to count her toes and 9 fingers.

Its an online video, its really stupid. You can Youtube whats 9+10 and see what I'm talking about

She might have been doing the 21 joke like mr. Paul said go to YouTube and look up what's 9+10

Its vine, you normie. n0t a meme

To find the sum of 9 + 10, you simply add the two numbers together. In this case, 9 + 10 equals 19. However, it's worth noting that there is a popular internet meme where someone jokingly claims that 9 + 10 equals 21. This meme originated from a Vine video, so your sister might be referencing that and laughing because she knows it's not the correct answer. But, please remember to be respectful when talking about others' intelligence, as everyone has different strengths and abilities.