Multi-touch technology is increasingly being used to support collaborative learning activities. However, to know how this technology can be used most effectively, we need to understand if collaborative interactions differ when groups are using multi-touch technology compared with other tools. In this paper, we compare the interactions of groups of 10 to 11-year-old students working collaboratively to solve three math problems in either a multi-touch or paper condition. The number of ideas raised, who proposed them and whether they were responded to, were coded to identify differences in idea development and interactions across conditions. Responses by students to ideas proposed by other students were coded. Results indicate that similar numbers of ideas were raised across conditions; student responses to ideas raised by other students were more likely to elaborate on the idea or combine it with other ideas in the multi-touch condition than in the paper condition. These results reinforce prior findings that show higher levels of collaborative engagement around ideas when using multi-touch than paper and extend our understanding of how this occurs.