ERÊs were originally designed as climbing/ building blocks to be used by physiotherapists in stimulation sessions for children with cerebral paralysis. Later, it was realized that they might be educationally effective as well as a toy for children and teenagers without special needs. A child or a young person may use ERÊs to make different products through the geometric /spatial cognitive process, designing them by building their own objects to meet the need to play /interact systematically. ERÊ modules are obtained by a mathematically sectioning a foam block without leftovers.