I was thinking of adding a link to Mira from our Books and Tutorials FAQ, but then I took a closer look at the Calculator tutorial.
It is a mishmash of two approaches in one project:
- 10 buttons but no Arrangements in the Designer
- Two text boxes for the numerical input later on in the same Project.
It' looks like the tutorial was generated by an AI, pieced together like Frankenstein's monster from other online tutorials.
I might recommend this as an exercise in critical reading, but not as a tutorial I would support at the blocks level.