The focus of subtracting decimals should be on students' understanding of number sense and operations, rather than making a specific computational process. The place value model teaches the student why the standard algorithm works.In the game, two numbers (random choice) appear. The student has to create a place value model for each one of them. Then, the student has to create a place value model for the result of subtraction of two and in the end the student has to write the number for the result of subtraction.In this app we play with place value models for decimal numbers up to 12.99. Every right answer takes 1 point, every wrong answer takes 0 points. When the whole procedure is completed, the funny figure announces the grade, for example: grade(0-4)/4. We have a random choice of decimals and so many possible numbers (0-12.99) for practising. Finally, we point out that it is an educational game, that students gain points and learn by having fun , a useful teaching resource for teachers in grade 5 and 6 in primary school and also a learning tool for parents in helping their children with daily homework.