It has the same downside than all activities, opportunity cost.
I teach math at the first year of university in Argentina. My kids (a bunch of 18 y.o., but I call them "my kids") start the semester and barely can solve a 2x2 equation system. At the end most of them can use the Gauss Method and the Simplex Method. I enjoy seeing the improvement, and also the challenge that they are very different. Some have a bad math background and we have to teach the rule of of the signs for integer addition. Some have a better preparation and ability and we can give some hints about deeper topics like the dimension that are covered very shallowly in the course.
Also, a few years ago I worked with teenagers training for the national Mathematical Olympiad. I had smaller groups so it was more personalized, and I have the same students for years. I still meet some of them from time to time. It's nice to see how they improve during the years.
In my opinion, if you get enough money+happiness to compensate the time investment, it's a nice activity.
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> I usually charge $12–20 Euro per session
I think it's a little on the cheap side. Last year I asked about the 1 to 1 private class that some of my coworkers do (with students of other universities, obviously not with their own students). The unofficial rule for the price was "1Kg of ice cream from Freddo" (one of the most expensive ice cream stores here) that today is like €17. That's the price for a good standard math class in not the most expensive country on Earth.
So, if you have more request than what you can handle, consider raising your price. Anyway, money is not the only metric, some in some case you can lower the price in exchange of happiness or interesting cases.
It has the same downside than all activities, opportunity cost.
I teach math at the first year of university in Argentina. My kids (a bunch of 18 y.o., but I call them "my kids") start the semester and barely can solve a 2x2 equation system. At the end most of them can use the Gauss Method and the Simplex Method. I enjoy seeing the improvement, and also the challenge that they are very different. Some have a bad math background and we have to teach the rule of of the signs for integer addition. Some have a better preparation and ability and we can give some hints about deeper topics like the dimension that are covered very shallowly in the course.
Also, a few years ago I worked with teenagers training for the national Mathematical Olympiad. I had smaller groups so it was more personalized, and I have the same students for years. I still meet some of them from time to time. It's nice to see how they improve during the years.
In my opinion, if you get enough money+happiness to compensate the time investment, it's a nice activity.
---
> I usually charge $12–20 Euro per session
I think it's a little on the cheap side. Last year I asked about the 1 to 1 private class that some of my coworkers do (with students of other universities, obviously not with their own students). The unofficial rule for the price was "1Kg of ice cream from Freddo" (one of the most expensive ice cream stores here) that today is like €17. That's the price for a good standard math class in not the most expensive country on Earth.
So, if you have more request than what you can handle, consider raising your price. Anyway, money is not the only metric, some in some case you can lower the price in exchange of happiness or interesting cases.
Take a look at the old posts by patio11 https://www.kalzumeus.com/2012/01/23/salary-negotiation/ (HN discussion https://news.ycombinator.com/item?id=24588379 (420 points | Sept 2020 | 263 comments)) and also https://www.kalzumeus.com/2012/09/21/ramit-sethi-and-patrick... (HN discussion https://news.ycombinator.com/item?id=4554669 (234 points | Sept 2012 | 87 comments))