Background. Studies have shown the great importance of early mathematical development as a predictor of subsequent success, which poses the question of how to organize preschool mathematical education with a view to the children’s age characteristics, including their cognitive development. In other words, mathematical concepts and actions should be formed with the help of teaching resources appropriate to the child’s development. Objective. To determine the e" ectiveness of three teaching resources (examples, models, and symbols) in formation of the concept of magnitude in older preschoolers (ages 6–7) with di" erent levels of executive function. Design. Four training programs (with 15 twenty-minute lessons each) were developed and conducted in a formative experiment for older preschoolers with di" erent levels of development of executive functions. ! e lessons addressed the concept of magnitude (length, area, volume), using di" erent types of teaching resources: exemplars (in traditional and game variants), models, and symbols. ! e total sample of 116 subjects (44% boys) was divided into 4 groups for each of the programs, plus a control group in which no sessions were conducted. ! e groups were equalized according to the initial level of development of concepts of magnitude and the level of development of executive functions. Results. ! ere was a statistically signi# cant increase in the quality of mastery of the concept of magnitude in three experimental groups (“symbolic,” “traditional,” and “traditional with imaginary characters”) compared with the control group. ! e formative e" ect of the “model-building” program showed no signi# cant di" erences from the e" ect of the child’s natural development (the control group). We also showed that children with a low level of regulation learned mathematical concepts more e" ectively with the “symbolic” program; children with a medium level of regulation with the “symbolic” and any variant of the “traditional” program; and children with a high level of regulation with the “symbolic” and “model-building” programs. Conclusion. ! e # ndings underline the importance of both the type of teaching resources used and the level of development of voluntary regulation, when teaching mathematics to preschoolers.