Note On a Mac with Xcode installed, or on an iPad with Swift Playgrounds, you can open this chapter as a playground. Playgrounds allow you to edit the code listings and see the results immediately. (Note in page 3) (I would like to open the chapter or book: Swift Programming Language in Swift Playground on iPad) https://books.apple.com/ve/book/the-swift-programming-language-swift-5-7-beta/id1002622538?l=en-GB Best regards

Experiment Create a constant with an explicit type of Float and a value of 4. https://docs.swift.org/swift-book/documentation/the-swift-programming-language/guidedtour