Popular online math games are available at Coolmath-Games.com, as of 2015. Titles on their popular list include "Fireboy and Water Girl in the Forest Temple," "Sticky Ninja Academy," "Bloons Tower Defense 3" and "Don't Cross the Line." Games on the site do not contain violence and are free.
In "Bloons Tower Defense 3," the player must defend a base against advancing balloons. The player accomplishes this by placing defensive turrets along the predetermined route of the balloons. There are a variety of turrets, each with different characteristics. The player must manage resources and position turrets effectively, as each turret costs in-game currency to purchase. In-game currency can be earned by destroying balloons and completing stages.