Just to give us something to type our experiments into, we will create an extremely simplistic app, one that will present a window into which the user can type a rate of sales tax and a pre-tax price, and will present the resulting price inclusive of sales tax.
It shall be called Sales Tax Calc. I know, it's not a brilliant name.
Create a new Xcode project called SalesTaxCalc, setting it to use Storyboards.
Drag four labels and two standard text fields ...