Successful problem solving begins with constructing mental problem representations and the identification of problem characteristics to clarify the solution. The purpose of the current study is to examine the design principles of learning supports promoting mental problem representation in the math problem solving setting. We investigated the mental problem representations and problem solving performance influenced by the formats of the learning supports. Through the analysis of participants' visual attention and solution notations, the current study found that problem solvers' visual attention on symbolic learning support increases whereas their visual attention on iconic learning supports decreases during the problem representation stages. There is a significant difference in problem solvers' visual attention on iconic learning supports between the successful and unsuccessful problem-solving groups. Unsuccessful problem solvers tended to disregard critical elements in the math word problem.