In the past technology products created to overcome accessibility and usability issues experienced by individuals with special needs have also resulted in greater usability for the wider population. Technology is increasingly being seen as a key component within the education of children with special needs and recently researchers have developed tailored approaches to involving this population in designing the technology. However, it is not known if these approaches could also benefit participation in a wider population. This paper investigates the potential benefits of using a new structured and supportive participatory design (PD) approach IDEAS, tailored to the specific needs of children with autism spectrum disorders (ASD), for mainstream schoolchildren. The development of this new approach is guided by the TEACCH program and additionally draws on ideas from existing PD approaches for children. A study has been undertaken to trial this approach with four design teams, two teams including children with ASD and two teams including mainstream schoolchildren. Their design task was to develop a mathematics game over a series of six design sessions following the IDEAS approach. The findings reveal that a structured and supportive PD approach can benefit both children with ASD and mainstream children. However, these benefits varied between and within different groups, with some children requiring the additional structure/support more than others. Future work intends to build upon these findings to develop a PD toolbox for a broader child population, enabling researchers to provide appropriate tailored support based on children's individual characteristics and needs.