Sumdog's contests are free to take part in. They let you compete against other classes - either locally or nationwide.
These are different from activities, such as competitions or challenges, which are only visible within your school. When you play in a contest, your class will play against classes from other schools.
Students participate in contests by simply playing Sumdog's games. Their scores will count towards their class' score in the contest. The score is a class average.
All contests last a week - from 8am on Friday, local time, to 8pm the following Thursday.
Students who answer 100 questions in a contest will receive an item for their Sumdog house.