9+10

21!!!!!!!!!!!!!!!!!!!!!(no i am not stupid)

19! Orrr... 21

9=3*3 10=5*2 so now 5*3=15 and 3*2 equals 6. add 15 and 6 which equals 21

-Hayley

hmm lets see...9+1=10 10+1=11 11+1=12 12+1=13 13+1=14 14+1=15 15+1=16 16+1=17 17+1=18 18+1= 21!!!!!!!!!!!!!!!!!!!!!!!!!!!! ITS JOHN CENA!!!!!!!!!!!!!!!!!!!!!!!!!!!DEEZ NUTS!!!!!!!!!!!!!!!!!!!!!!!!HAHAHAHAHAHA

Jk

Thats getting old