In the card game "Calculating up to 20," children practice addition and subtraction within the number range of 20, reinforcing their basic math skills. Following a simple trump game principle, the goal is to win the most tricks, with the calculation task yielding the highest result winning. Variants such as "Matching Game," "Stacking Game," and "Black Widow" provide variety and continuous fun. The cards offer a total of four gameplay options for 1-5 players aged 6 and up. All gameplay options of this card game promote flexible and confident calculations within the number range of 1-20. The variants differ in difficulty, allowing each player to find their own challenge. The rules for all game variants are quickly explained, making it particularly easy to use the handy game cards even during breaks or on the go. In the "Matching Game" variant, players aim to find suitable tasks that result in answers from the number range up to 20. Those playing "Black Widow" collect pairs of calculation tasks that have the same result. In the "Stacking Game," tasks and results are stacked appropriately. This makes calculating really fun and is also suitable for independent work in elementary school.