Introductory SW Engineering Projects (HS level)

mtapman writes: List three suggested introductory software engineering projects for a high school level student. Assume the student can do basic math (up through Algebra I or Statistics I) but is new to logic and computer science. Each project should take no more than four hours to complete including research, coding, and testing.The intent is to introduce the student to software engineering (and computer science) through practical and fun examples. Classic CS problems are welcome. One of the key criteria is available research/reference material to allow the student to make progress with 30-60 minutes of online research.

Some ideas that came to my mind (not necessarily good ones) are: (1) pick a sorting algorithm and sort a list of ten words alphabetically, (2) write a program to convert characters from lower to upper case, (3) write a program to divide two numbers in two different programming languages and compare the results to determine the differences between the languages.