價格：免費
檔案大小：10.2 MB
版本需求：需要 iOS 8.0 或以上版本。與 iPhone、iPad 及 iPod touch 相容。
支援語言：英語
Learn to add and subtract. Starts with numbers from zero to 4, and gets more challenging as you get the answers right. Once you have a handle on addition, adds subtraction problems. Expected to be useful before or about first grade (ages 4-7).
支援平台：iPhone, iPad