Annika Riz loves math more than anything. She's trying to teach her dog, Prime, to count. She's determined to beat fellow math whiz Simon Ellis in a Sudoku contest at the public library. She even sleeps under number-patterned sheets. But Annika's best friends Kelsey and Izzy think math is boring. All they care about is the upcoming school carnival: their principal is going to be dunked in a dunking tank and their class is going to have a booth selling home-baked cookies. But then disaster foils the friends' cookie-baking plans. Can math save the day?