Abstract: The structure of applied arithmetical problem is the main factor thataffects its solving. The author tried to find out the thinking process ofschoolchildren in solving problems of different structures. Eleven testswere made on the subjects' ability to differentiate problem structures;distinguish between necessary and unnecessary components; generalize andclassify problem structures; supplement one or more missing links; correct,reorganize, expand or compress problem conditions and etc. Analysis ofthe developmental process of the children's cognition of the structureframe, the structure of quantitative relation and the plot structure of theproblem showed that experimental teaching, which converged with the pro-cess, promoted the development of children's cognition.

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