###### – an app for practicing and deepening elementary arithmetic skills with a special focus on the use of informal feedback to promote comprehension processes.

Rechnen mit Wendi is an exercise software for the initial mathematics lessons, which was specially designed to support children with special needs in the acquisition of mathematical skills (dyscalculia) in primary and special schools.

After evaluating the first version, which was created as part of my admission paper for the state examination, the software was revised and completely reprogrammed.

The learning software offers exercises for addition, subtraction and (quasi-)simultaneous quantity recognition in the number range up to 6, 10, 12 or 20. The basic tools are virtual tiles, which are presented either with or without a structured tens or twenties field. The moving turning tile "Wendi" accompanies the student during the calculations.

There are four games available that can be adapted to the child's individual learning level:

- Flash vision: Here, quantities must be recognized in a flash without counting.
- Addition
- Minus calculation
- Addition and subtraction mixed

In this video you can see Wendi in action:

What is special about this exercise program is the targeted use of the computer's capabilities to support the mathematical understanding of numbers and arithmetic operations. It was designed based on the findings of a research project that examined the possibilities of supporting learning on the computer for children with arithmetic difficulties. Children who have difficulty understanding mathematical relationships in particular fail in exercise programs because of the often unhelpful feedback, because they cannot learn from mistakes and tend to become demotivated. This exercise software therefore contains clear feedback and thus offers more than just a "right" or "wrong". The learning program offers the following didactic functions, among others:

- Quantity representation of the operations with proven structured mathematical visualization aids (tiles in the tens/twenties field), which enable structured quantity recording according to the "power of five". The field can also be hidden if desired.
- If desired, plus and minus tasks can be set up clearly and step by step. This makes it easier for children to understand the operations as a process and to understand how numbers and quantities are related to each other and what the operation symbols + and - mean. For example, in the minus task 8 - 3 = _, 8 dots initially appear. Then 3 dots move to the side. This step-by-step structure has many advantages over a static representation (for example, crossing out the quantities). This can be used to specifically promote intermodal transfer (ie the mutual translation of the calculation task and task representation) between mathematical representations (representation levels).
- The children can see for themselves whether their solution is correct or why it is wrong. The input set is visually compared with the solution set. This makes it easy to see whether the result is correct or why the solution is wrong. This gives the children the opportunity to identify the causes of errors themselves and to learn from mistakes.
- The math race, in which Wendi competes against his opponent, is particularly motivating for the children. For every correctly solved task, Wendi comes a little closer to the goal, while if he makes a mistake, his opponent moves a little further ahead. For every exercise sequence won (5, 10, 15 or 20 tasks), he wins a star.
- The program is individually customizable (adaptability), for example the number range, the type of task presentation (numbers & quantities, quick sets or just numbers), the scope of tasks per game, etc.
- A learning-focused design of the program interface based on insights from human-machine interaction prevents unnecessary distraction and complexity of operation and puts the learning content at the center.
- Students with motor disabilities can control the learning software using buttons. The space bar jumps from one screen object to another, and Enter activates the highlighted element. Alternatively, control is possible using just one button (scanning).
- The program is available in German and English. The language used adapts to the language set in the operating system.

The app offers a variety of options for adapting the task presentations to the child's level of learning, for example the number range, whether zero should be included, the task presentation, number of tasks, help, etc. The task presentation in particular should be adapted to the child's level of learning under "Settings":

- For children who are just learning the operation, the option "Quantities and Numbers" should be selected. It is advisable to choose the step-by-step presentation so that children can better understand how the task is created and discover connections between the numbers, operation symbols and quantities.
- For children who have a basic understanding of the operation but still mainly calculate by counting, the "flash view" option should be selected. Here, the quantities are briefly displayed but then hidden, making counting more difficult. It is a good idea to discuss and practice with the children beforehand how quantities can be understood without counting (eg by using the "power of five"). The flash view game can also be used for this.
- For children who already have a solid understanding of the operation and can calculate without the aid of visual aids, the option "Numbers only" should be selected. The operation sets are then only displayed to check the solution. Non-counting calculation strategies should be discussed in advance.

Conceptual considerations on the learning software can be found here.

I would be very happy to receive suggestions, reports of experiences, etc. in the comments or via the contact form.