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Math Excuses

A while back one of my readers and top commentators sent me a picture of a clock, knowing that I would find it amusing. Here it is:

9 Clock

(Added 9/26/2013: In the comments to this post, you will see that several of my sharp readers have "done the math" and determined that there's a problem with the math at the 5:00 position. That's the picture that was sent to me, so I'll just have to leave it. You can see their corrections in the comments section of this post.) 🙂

It reminded me of a picture of a clock I featured in a post called History of Math Teaching in the US. In that post I related that each year now I have at least one student who does not know how to tell time with an analog clock. As we face learning time telling again in my beginning languages classes, I'm going to continue to keep analog clocks before my students' eyes, but much simpler than the clock above. 🙂

As I have further contemplated why students do not do well with mathematical concepts, I wondered if, for some, it's simply because they don't do their homework. Today's post is a list of the top ten excuses students give for not doing their math homework. I'm not mathematical enough to understand the humor in some of these, and I even did my homework, always!

Top Ten Excuses For Not Doing Math Homework

1. I accidentally divided by zero and my paper burst into flames.

2. It's Isaac Newton's birthday.

3. I could get only arbitrarily close to my textbook, but I couldn't actually reach it.

4. I have the proof, but there isn't room to write it in this margin.

5. I was watching the World Series and got tied up trying to prove that it converged.

6. I have a solar powered calculator, and it was a cloudy day.

7. I locked the paper in my trunk, but a four-dimensional dog got in and ate it.

8. I couldn't figure out whether i am the square of negative one or i is the square root of negative one.

9. I took time out to snack on a doughnut and a cup of coffee. I spent the rest of the night trying to figure which one to dunk.

10. I could have sworn I put the homework inside a Klein bottle, but this morning I couldn't find it.


Do you have remember any excuses you used for imcomplete math homework? Please add them to the comments.

After Life Group recently as we hung around and talked, we ended up talking about high school geometry. Some of us loved doing proofs, and others (not surprisingly) didn't. In high school, I was one of the nerdy kids in the class who wanted to be able to do a proof with the least number of steps. Here's a cool proof that even non-math readers will enjoy. (Hint, you almost have to read it out loud.)

How do you prove in three steps that a sheet of paper is a lazy dog?
1. A sheet of paper is an ink-lined plane.
2. An inclined plane is a slope up.
3. A slow pup is a lazy dog.


"I stopped understanding math when the alphabet decided to get involved." — unknown student who did not enjoy algebra


A math teacher is a person who talks in someone else's sleep.

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5 Comments on “Math Excuses”

  1. #1 Vikki
    on Sep 25th, 2013 at 8:28 am

    I too was one of those nerdy people who loved to work proofs. At the end of each chapter I would to go to the end of the questions, where the extra credit problems were, and work them just for the fun of it. Also, like you, in the most efficient way with the least amount of steps. Needless to say, I got an A in that class. My best friend, who sat next to me in geometry class, hated them and thought I was totally nuts. She didn’t catch on to solving proofs until well into the class and almost flunked out of it.

  2. #2 Vikki
    on Sep 25th, 2013 at 8:29 am

    Oh, and I forgot to add, that clock in on the 9’s. Always wondered what that expression meant, not I know 🙂

  3. #3 Theron
    on Sep 25th, 2013 at 12:47 pm

    #8: i is the square ROOT of negative one. i am the square of negative one only if I was born between one and two years ago and my capitalization is bad.

    By the way, the clock is incorrect at 5:00.
    sqrt(9!) – 9/9 = sqrt(362880) – 1 = 601.395
    It should be:
    sqrt(9)! – 9/9 = 3! – 1 = 6 – 1 = 5

  4. #4 Abby O.
    on Sep 25th, 2013 at 9:41 pm

    For the 5’s place of the clock, the factorial needs to be outside of the radical symbol. As written, the expression is about equal to 601.4.

  5. #5 Carrie
    on Sep 30th, 2013 at 10:54 am

    Thanks for the introduction to a Klein bottle! That clock is something else.