In the 2nd-grade mathematics textbook by (School 2100 program), pages 4 and 5 of Part 1 focus on reviewing 1st-grade material, specifically "Numbers from 1 to 20" and basic operations. Page 4: Reviewing Numbers 1–20
). For example, comparing the number of objects in two groups or simple numeric values like
Use resources like GDZ.ru or Megaresheba only to check your final answer.
Attempt the task on your own to strengthen your logic.