Addition Subtraction Kids is an educational app designed to help children in kindergarten or grades 1 and 2 learn math in a fun and effective way. Developed by Vu Ngoc, this free app combines games and math lessons to engage children and make learning enjoyable.

The app features three math books, each with 30 lessons on addition and subtraction. The lessons start from easy and gradually increase in difficulty, allowing children to progress at their own pace. The app also includes a map that guides children through the lessons, with each level unlocking new locations, monsters, and collectible cards.

When solving addition and subtraction problems, children are given the opportunity to correct their mistakes. If they make a mistake, a board will appear to help them count again and choose the correct answer. However, if a child makes the same mistake three times in a lesson, they will not be able to proceed until they practice and complete the lesson successfully.

As children complete lessons, they are rewarded with lucky cards that they can collect to increase the fun factor of learning math. Parents can also track their child's progress on the route map, allowing them to see the number of correct and incorrect answers their child has achieved.

Addition Subtraction Kids is a great tool for parents who want to supplement their child's math education and make learning enjoyable. By combining games and math, this app helps children develop their math skills while keeping them engaged and motivated.