# Learn Math (10 tips)

Posted on August 17, 2006, in math, imported

One of the most common things I hear from my programming buddies is, “I wish I knew more math.” I think I tend to hear this from my friends because when I was an undergrad earning my BS in CS I took my time to also pick up a BS in math. Most of my friends know this and so they tend to ask me questions about math and learning it.

Well guess what? Even with a four year degree in math, I feel the same way. Oh, perhaps I’d say it differently, “I wish I could remember and pickup more math” but it’s the exact same feeling. As programmers, math is very important and we know that even when we’re just writing SQL statements or producing XML transformations.

So how do we learn more of this math? Well, it’s going to take time and commitment and I admit I don’t have it all figured out, yet, but I’ve been spending some brain time on it trying to figure ways to get there.

There are several important ingredients you’ll need, but before I dive into that let me explain some of the ways my learning style changed as I studied math in my undergrad. I consider these changes you might try to bring about in yourself so that you’ll pick up the math more easily.

1. Learn to learn. Simply put, reading it and thinking about it are not enough. As an aside, if learning the math doesn’t feel difficult, you’re probably not actually learning it. To really learn something and expand your mind is hard work and you’ll get tired, frustrated and discouraged. Just remember, your mind is similar to a muscle. You have to exercise it and let it rest and recover. Exercise is hard work, but the benefits are worth it.

2. Definitions are probably the most important thing you’ll ever learn in math. See point 1 for my definition of “learn”. When you really get the definition of something, many theorems just make sense and after you get point 4, proving them is just a matter of explaining to someone why the theorem makes sense to you. Of course not all theorems are this way, and you should definitely try to capture any clever reasoning behind named proofs. These patterns of reasoning will resurface in your later proofs.

3. Write it all out, everytime. Primarily I mean definitions and statements of theorems. Also, think about it while you write it. Stop and pause, think about where you could take short cuts in phrasing the definition of something. Does that change the meaning? Why do you suppose the definition bothers to include unique identity instead of just identity? Are there theorems you’ve learned about this object that would fail to hold?

4. Work the exercises, and write out all the details of the proof, even if the proof is given in the book and you think the omited details are “obvious”. Learning to phrase the “obvious” mathematically is immensly important. Additionally, you may discover something by exploring the “obvious”. Entire branches of mathematics have been discovered by people exploring the “obvious”. See the history of non-Euclidean geometry for background (some info here: http://universe.sonoma.edu/activities/geometry.html).

5. Infinity, sequences and real numbers (aka real analysis), induction, and group theory. When you learn each of these concepts your understanding of programming will actually improve. You’ll see things in new ways. Even things in nature. There’s probably a million other things that you can learn to expand your mind in the same way, but I learned the above list in that order and it changed me and my way of seeing the world. I’m confident it will do the same for you because I witnessed similar changes in friends that I studied with.

Now, on to the things you’ll need to in order to be more successfull in your studies.

6. You need good text books. Text books are not created equally. What makes a text book good is hard to define. Basically, the definitions need to be good and progress nicely. The book needs to start where you are and lead you where you want to go. Some of the theorem and exercises should contain typos and incorrect solutions. This is highly counter intuitive but very important if you want to learn the subject.

Since you’re trying to learn the material, not just absorb it, you’re going to be hand checking the theorem proofs and working the exercises until the logic makes sense. Here is one possible outcome I’ve experienced several times with flawed exercises: When you come to one that has a flaw you might at first go with it. Then you might work it a bit more and realize you’re not getting it. This stuff is confusing. But then you think, “wait, I made it this far, why is this stuff confusing?” Back to the definition you go. Do you really get the definition? Yeah, I guess so but if that’s the case, then this is really a bad way to put it. Oh wait, it’s not just a bad way, but it should be this way. Oh! I get it, and that theorem over there seems so trivial now… Another possibility is that you think you have found a typo, but even after “fixing” it, it’s still not quite right. In this case, often you’re wrong and you have to figure it out! Doesn’t this sound familiar? It’s like this, you read it, interpreted it, wrote it down and now it doesn’t work like you wanted and you have to spot the problem and figure out the solution. Oh, I just described debugging something you programmed. Learning math can actually improve your programming without teaching you anything specific to the code you’re working on. One last comment on the text book. I don’t know how to get good text book recommendations. Perhaps amazon reviews are okay, but I want to trust the reviewers and know that they will recognize a good text book before I trust them here. Perhaps it would work to find a quality researcher and look at their books.

7. People to talk to. You need friends that you can talk to about the ideas you’re learning. Now that I don’t have classrooms full of other math undergrads to talk with I don’t know what to do about this aspect. Perhaps I need to go back to school or maybe I can find forums online. I should look into this and let you know what I learn.

8. Subjects that you care about. Ever dreamed of cracking some crypto system? Ever wondered why a Turing machine is capable of computation? What is type inference? How does the four color theorem work? I’m sure you’ve wondered one of these or similar questions. But perhaps you don’t care at all about Fermat’s last theorem. So just to state the obvious, remember to pick something that has a pay off for you emotionally. It fills a curiousity or dream. You’ll need this as motivation when the learning gets hard.

9. Learn time budgeting. The best time budgeting technique I have picked up is this: Take a calendar that gives your week in tabular form. Each day is a column and the days are split into rows about 30 minutes per row. Whenever you have something that you’d normally stick on your TODO list, block out a chunk of time on your calendar. Let’s say you need to go to work, wash the dishes, cook dinner, take out the trash and study your math. Well, you start by blocking out the time for work, then fill in 30 min for chores and an hour to cook and eat dinner. Suddenly you see that you really can’t afford to spend 2 hours with your math book tonight. Maybe you block in 30 min with your book. Even though you want to get through chapter 3 before you crack open your other book you won’t be able to do it this week. But that’s okay, because you’ll be making lots of these appointments with your book and eventually you’ll get through it.

Now if you do this for each day of your week and try to live out the schedule exactly as it’s written you’ll start to feel like a robot and there is a solution to that feeling. I’ll explain with an example. On Tuesday you’re supposed to be cleaning the bath tub at 6pm but you really want to watch a movie (scheduled for Wednesday). So here is the rule: You can change activities on your calendar as long as you follow some law of conservation. In this case, you could swap the days of the activities. Just live up to it. There’s no point in bothering with this sort of time budgeting if you can’t keep the promises you make with your calendar. In fact, you probably won’t get much done of what you mean to.

10. Change your life gradually. The most lasting ways of changing your life generally happen gradually — not over night. So work up from one math text a year to one every 3 months. Start at something reasonable and increase the load as your interest increases. Sink or swim works for some things, but I find it unlikely that it will work here.