When will I use this? This is a legitimate question. In today’s world we have calculators to do computations. And calculators do not make careless errors. So, even teachers can fall into the trap of thinking there is no reason to learn math.
I teach college students, and when the math gets to such things as algebra and trigonometry the question is often asked. The answer is simple, but getting the students to believe the answer is not so simple. Math develops a thought skill that permeates most fields of study.
Let us look at an example. Math develops a logical approach to solving problems. So, a historian studying a time period for a certain country comes up with an edict issued by a king. Rote learning would stop with the fact the edict was issued, but at the higher level required of historian there must be an understanding. Examining a chain of events, and what that king expected to achieve are a greater focus than the document itself. This level of understanding requires logic. This same skill can be developed in solving an algebra problem, but the connection is not apparent on the surface. So, that math course can be useful years later by an historian.
A calculator cannot develop a thought process. But, I have had a student tell me that she always was told to “pull out the calculator” when it was time for math throughout elementary and secondary school. The attitude of her past teachers is unsettling, and a disservice to the students.
Knowing there is a use, even a less than obvious use, makes the desire to know math greater.