Addition and Subtraction to 20

1. Add/ Sub to 20, part 1 (Problem-answer matching)

Link up - The level consists of 10 questions and all of them are practiced in every game round. The player's task is to link the 10 questions in the colored boxes with the most appropriate answers in the white boxes. Each colored box can only be linked to one white box and vice versa. The student receives feedback on the links after submission and has 1 attempts to get all the links right. Questions have text-to-speech in English. Answers have text-to-speech in English. There is no time limit. When the student has linked all the boxes correctly, the game round is completed. If it is too difficult, the player can click the button labeled Cancel - then the correct links are displayed - and try to complete the level again.

2. Add/ Sub to 20, part 2 (Problem-answer matching)

Link up - The level consists of 10 questions and all of them are practiced in every game round. The player's task is to link the 10 questions in the colored boxes with the most appropriate answers in the white boxes. Each colored box can only be linked to one white box and vice versa. The student receives feedback on the links after submission and has 1 attempts to get all the links right. Questions have text-to-speech in English. Answers have text-to-speech in English. There is no time limit. When the student has linked all the boxes correctly, the game round is completed. If it is too difficult, the player can click the button labeled Cancel - then the correct links are displayed - and try to complete the level again.