Common features and classifying
Find the common feature of a set, sort shapes into groups by two features at once and find the odd one out.
- Germany: grade 5
- Russia: grade 2
Guide
In Russian schools (Grades 2-3, "Mathematical information") children find the common feature of a set of things and classify by one or two features, for example shapes by colour and by shape at the same time.
With two features there are more groups: red circles, red squares, blue circles, blue squares. Each shape lies in exactly one group, and all the groups together make the whole set.
Ask the child to invent a classification of their own, for example dishes by material and by use. This prepares for tables and charts.