Completing sets

Tips on how to use this exercise at home and at school.

Completing sets

Early math concepts


In this exercise, the child knows the selected objects but has to figure out by what criteria to sort them to find which object belongs or does not belong among the others. The child is probably familiar with this type of task from various worksheets and activities from kindergarten or school.


Why is this exercise important?
The exercise focuses on promoting sorting according to the given criteria. It is important that the criteria are clearly defined and that the objects can also be explicitly classified. The child learns to think, analyse and structure their thoughts. By sorting, the child also learns conceptual precision, which is important in mathematics.

Who is this exercise suitable for?
Mainly for preschoolers, but it is also suitable for older children who need to develop their language skills.

Methodological recommendations
Either read aloud the instructions to the child, play them from the app or let the child read them by themselves.

The child looks at the objects and explains how to proceed and why. Ask for the reason behind their thinking and if another object in the picture could also belong to the group and why. In this way the child thinks, learns to argue and develops language skills through their verbal reasoning. This way, they learn in a much deeper and more complex way.

Tips for similar activities outside the app
Try a similar game with your child, but reverse the roles. Challenge them to sort the different objects (e.g. toys, blocks or buttons) by themselves according to criteria chosen by them. Your task is to recognize the criterion according to which the child has divided them (for example, all objects with the same animal motif, the same colour, material, etc.).