價格：免費
更新日期：2017-10-11
檔案大小：17.9 MB
目前版本：1.2
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
Do you think subtraction or addition is easier?
You will use subtraction and computational thinking to reduce the numbers to zero.
Easy is not it? But do not be subjective because it will be difficult if you subtract a few wrong steps. It's harder when the numbers will grow and your speed must be increased.
支援平台：iPhone