Mental Math

 $12\ \times\ 2=$  

 $9\ \times\ 3=$  

 $105\ +12=$  

 $2,000\ +100\ +30\ +9=$  

 $27-9=$  

 $562\ -5=$  

 $250\ -250=$  

 $98\ +0=$  

 $18\div3=$  

Alia collected 2,408 stickers, Mahra collected 2,500 stickers. How many stickers do they have altogether?