Practice at home. Just because your teacher has set aside 10 minutes or so per day to play First in Math doesn't mean you can't play it from home. Talk to your parents about setting aside 10 additional minutes of time during the afternoon or night to complete more games and problems.
Set a goal of earning 2 stickers per minute. If you play First in Math for 20 minutes everyday, and you earn 2 stickers per minute, then you'll get to 1,000 stickers in only 25 days. At that rate, you could even end up earning a "10,000-Sticker Achievement Award" by the end of the school year.
Complete the skill sets so you can play the wheel games like Ten Wheels, Fraction Wheels and 24 Wheels. Every time you complete a skill set, you get 100 credits that you can use in the wheel games. For every sticker you win, you earn 100 credits multiplied by the number of stickers. So if you earn 4 stickers in the game, you'll earn a total of 400 stickers overall.
Start with easier games like Number ZOO and Yakkity Yak, which allow you to quickly earn stickers. As the school year passes and your math skills improve, slowly make your way to harder games like What's My Angle, Missing Links and Get a Clue. These games give out the same number of stickers, but they're more difficult and may take more time. However, the extra time is worth it because you'll become an even better First in Math player.