Milli, Geo and Bot reward themselves for cleaning up Umi Headquarters with a trip to the playground. But just as they’re getting ready to leave, they get a call on the Umi Alarm from their friend Mia. A storm has left the sandbox, swings, slide, and bouncy bridge in disarray and until everything gets fixed, the park will remain closed. The Umizoomi team tackles the task using mighty math powers and soon the playground is as good as new. The park ranger unlocks the gate and Milli, Geo and Bot join Mia and her friends for some hard-earned playtime.