This site hosts archives for the Subject Contest "Eureka" , including protocols and tasks for 5th-grade mathematics from various years (e.g., 2013–2016).
They provide specific problem sets and solutions for their 5th-grade math olympiads, covering topics like invariants and combinatorics. spishi.ru po matematike 5 klass konkurs evrika
Simplification of expressions, equations, and solving text-based problems. Geometry Basics: Points, lines, segments, and angles. This site hosts archives for the Subject Contest
Materials for the Junior Eureka Correspondence School often include downloadable tasks and answers specifically designed for 5th-grade students. Typical 5th Grade Math Contest Topics spishi.ru po matematike 5 klass konkurs evrika
Предметный конкурс "ЭВРИКА" - Математика
Most Eureka-style competitions focus on logic and advanced application of the standard curriculum: