How do you identify one capable to teach CS, capable to teach ages K-12, and willing to work for very little pay? Is the goal to train existing teachers (would they make more money because of it?), or hire a CS veteran to teach?
I think the best way to do this is to hire on CS veterans who want an early retirement but still need the health benefits and wouldn't mind a bit of spending money. Especially targeting people who are moving from a higher CoL area to a lower CoL area. Have them teach a half load on a 2/3 salary and with full benefits.
This gets complicated because of teacher's unions, but I think it's the best bet at getting high quality folks in CS classrooms.
Others will mention HS math teachers. Having spent enough time in US k12 classrooms to have an opinion on this topic, I think this can work out really well, but I'm not at all convinced it's a panacea. Mostly because many, many HS math teachers have learned how to teach specific math courses, but don't actually have a firm understanding of mathematical thinking in general. Training them to become CS teachers will fare about as well as teaching history teachers to become CS teachers (again, it can be great but lots of variance).
Teach the math teachers how to code, and they become your CS teachers. This is more or less how my HS got enough teachers to teach the CS courses, as they made it mandatory for all students to learn.
Learning how to code is easy; a lot of teachers can do it. Learning how to debug is quite a bit harder. Learning how to debug someone else's code is a lot harder. But this is essential in being able to teach coding effectively (not debugging someone else's code as such, but being able to find the bug and steer the student into a way of finding it themselves).
Your proposition also assumes that you have enough Maths teachers, which Australia is certainly lacking (for the same reasons as OP)
This is also how my high school did it. It didn't work out well, although as far as I know they're still teaching. These weren't bad math teachers: they were probably some of the best in the school; it's just that the couple months or a year of training they must have received was clearly not enough for them to handle those classes at all.
My guess would be training. You can have an online-supplemented course where most of the material is pre-canned and the teachers know just enough to guide the students through a semester or a year of class.
I doubt they intend on teaching much beyond the basics at that level, which shouldn't be hard for any teacher to learn.
Nope, this doesn't work. You get teachers who can basically teach students to memorize a bunch of computer science topics, but not those that can help at all in helping students when their code inevitably doesn't work.
