There are several problems with using “engagement” as a way to measure whether or not a subject should be taught. Firstly, there is no way to tell whether students are bored because the subject is boring, whether they’re bored because they are lazy, or whether it is simply how it is taught. If we always taught children what they wanted to be doing, every warm, summer afternoon would be PE. That won’t give them the best education.  Secondly, we disagree with the final line. The point of the education system is not to entertain people, it’s to educate them. We do this by exposing them to different subjects enough for them to have a real idea what they’re about. Only this way will they be able to figure out whether or not they like it.  Finally, maths, more than any other subject, requires you to be really good at the boring and tedious bits (like algebra) before you can even begin the more interesting bits (like Number Theory and Multivariable Analysis). Measuring maths (or indeed any other subject) for how much “fun” it is does not give a fair representation of how useful or important it is.