Physicists estimate that 47% of the energy in the universe is stored in stars, and the other 98% rages inside human children. Release your child's unyielding cosmic energy with today's Groupon: for $10, you get three admissions to Pop-In Playtime at Pump It Up of Littleton (up to a $21 value).

Pump It Up's hallowed, padded halls brim with all manner of inflatable gadgetry for the bouncing, sliding, and somersaulting enjoyment of pint-sized clients. All of the amusement center's polychromatic bounce arenas and slides are open to visitors during pop-in play-time, giving kids the chance to blow off steam and make important social connections during discussions of Clifford as an allegory for industrialism. The playpen's staff is vigorously trained to watch for unsafe situations and keep each air-filled apparatus clean and hygienic.

Parents are free to bounce with their children during the open-play session, though they are required by kid law not to show how much they are enjoying it. Browse the event calendar to find sessions that fit into any child's heavy schedule of school events and Model–Model United Nations meetings.