[Establishing methods for assessing the degree of difficulty of exercises in mathematics for younger schoolchildren].
D001794:Blood Pressure; D002648:Child; D006801:Humans; D007858:Learning / Q000502:physiology*; D008433:Mathematics; D008722:Methods; D011930:Reaction Time / Q000502:physiology; D012881:Skin Temperature; D014785:Vision, Ocular / Q000502:physiology
Obosnovanie metodov otsenki stepani trudnosti zadaniĭ po matematike dlia mladshikh shkol'nikov.