Please note, this blog entry is from a previous course. You might want to check out the current one.
Get the Calculator working as demonstrated in lectures 1 and 2. The Autolayout portion at the end of the lecture is extra credit, but give it a try because getting good at autolayout requires experience. If you do not do autolayout, be sure to position everything so that it is visible on all iPhones (i.e. the upper left corner of the scene).
I finished this task already during the lectures, including lecture #3. For convenience sake (mostly mine) I will base the follow tasks on the code from the end of lecture #3.
The complete code for the task #1 (different branches for end of lectures #1, #2 and #3) is available on GitHub.