00489naa#a2200169#i#450# EN\INFRA-M\bibl\1536 20240920022209.5 1998-0728 20140217b2014####ek#y0engy0150####ca RUS RU Division of sum by number (mathematics lesson in the 4th Grade) Journal article Moscow INFRA-M Academic Publishing LLC. 2014 5 с. Journal article local Semikopenko L. Yu. zh-szf.ru