Answer:
4
Step-by-step explanation:
If she wants to put 2 on each invitation, then we multiply the amount of invitations she has by the amount of stickers going on each invitation. 7 times 2 is 14.
She has 10 stickers, and she needs 14 in total, so we subtract 10 from 14 and we get 4.
In conclusion, the girl needs 4 sticks more