Almost all of the activities here have been trialled (and hopefully later improved) in my own classroom.

I find that what I need in my S1 and S2 lessons is fairly short activities
that are versatile enough to come anywhere in a lesson,
and which shed light on a syllabus topic in a fun way that I can later reinforce.

The syllabus I'm most used to is MEI.
The good news is (I hope you will agree with me) that the S1 and S2 modules, certainly with MEI,
are not so packed with syllabus material that it becomes hard to justify using tasks like these.