Rakin (Math App for Children) is a specially designed learning app for preschool and primary school children (www.rakin.academy). It helps children acquire fundamental mathematical skills in a playful and digital way. The goal of the app is to make learning mathematics enjoyable and to facilitate a smooth and lasting transition into school learning.

The app is based on a scientifically grounded developmental model of mathematical competencies (Fritz, Ehlert & Leutner, 2018). This model describes how children, starting from the age of three, develop mathematical abilities in six consecutive levels. Research shows that each level must be systematically mastered to build a secure foundational understanding. For children aged three to six, the first three levels are particularly relevant, and these form the structural foundation of Rakin.

Rakin is divided into three progressively structured worlds, each representing one developmental level:

- Level 1: Children become familiar with the number word sequence, understand the meaning of individual numbers, and learn to count and enumerate quantities.
- Level 2: Children recognize relationships between numbers and develop a mental image of a number line on which numbers are arranged in order.
- Level 3: Children understand numbers as quantities composed of individual elements and learn to break numbers down into subsets.

To support systematic development, a checklist with specific competencies for each level was created (Karahisarlioglu & Fritz, 2024). This served as the basis for the app’s design, ensuring that all relevant mathematical concepts are covered and promoted in a playful manner throughout the games.

On this basis, Rakin is suitable both for supporting children who need help building solid foundational skills and for further developing the competencies of more advanced learners. The app can be used flexibly in preschools, primary schools, or at home, allowing for individual adaptation to each child’s learning needs.

To make the learning process engaging and effective, Rakin includes a wide variety of games organized into three themed worlds—each aligned with one of the three described levels. Every game targets a specific mathematical skill and provides children with clear, narrated instructions and short demonstration videos to support understanding. During gameplay, children are continuously accompanied by a guiding character who provides motivational feedback and leads them step by step through the activities.

Through this careful combination of pedagogical rigor and playful design, Rakin successfully supports sustainable mathematical learning. It combines scientifically grounded content with age-appropriate playfulness. Thanks to its clear structure, targeted skill development, and motivating presentation, the app offers an ideal foundation for fostering each child’s individual progress and long-term enjoyment of mathematics.

The Rakin app was developed by the Akademie Wort+Zahl (https://akademie-wort-und-zahl.de) and CEDETI (https://cedeti.cl), and funded by the Rolf-Lappe Foundation (https://rolf-lappe-stiftung.de/rakin).