Add and subtract within 20
The description of Add and subtract within 20
This app was designed to help children to practice and improve their skills in adding and subtracting numbers up to 20. Starting with the most simple problems the difficulty gradually increases when the child makes progress. For a better learning experience the app keeps track of all incorrect answers and repeats those particular math problems more frequently. You can review where your math skills are weaker, this is especially great for parents who want to see where their child may need help and more practice.