These students very accurately and thoroughly demonstrate their ability to perform a variety of mathematical calculations and show their understanding of the steps of each process.

这是4~8年级的小朋友在苹果电脑的 Xcode 开发环境中用 Swift 编程语言实现的 iOS 应用。动滑轮和静滑轮半径不同时，转速的同步是个小小的挑战。

This 4th grader is proud of his understanding of the physics behind a pulley system.