Answer:
2739 stickers
Explanation:
So first, Derrick has 304 sheets of stickers and 12 stickers on each sheet. You need to find the total number of stickers he has before you do anything else. To find this out just multiply 304x12. When doing this you get 3648. Now that you have the total number of stickers you can subtract the amount he gives to his friends. Take 3648 and subtract 909 from it. When you do that you get 2739. So, Derrick has 2739 stickers left over. Make sure to add units!