Math = Love: Happy Numbers Make Me Happy :D

Tuesday, June 9, 2015

Happy Numbers Make Me Happy :D

Do you ever have one of those days where you have no clue what to do with your students so you go to the internet and find a random activity to give them that you've never actually done yourself?  In my defense, this happened AFTER testing in the last couple of weeks of school.  And, the reason I'm blogging about it is that it turned about to be an amazing activity!

I downloaded this Happy Numbers worksheet from here.  I replaced the Word Art title with a pretty font.  And, I Americanized the spelling of the word "colour."  Other than that, I left everything exactly the same.  

Happy Numbers are something I've never studied before.  They certainly aren't part of our math curriculum here in Oklahoma.  But, there's something special about this activity.

The thought of having to complete this process for 100 numbers sounds SCARY, INTENSE, NEVER-ENDING.  There has to be a short-cut, right???

There is.  Just don't tell your students what it is.  Let them discover it for themselves.

We read through the example on the handout.  Some students were extremely confused by this, so we had to go over it multiple times.

One of my classes was really struggling with getting started.  I worked this example on the board with them as a class.

It turns out I should check my students' arithmetic as we go and not just write down whatever answer they call out.  Can you see where we made a MAJOR mistake???  Oops...

Here are some pictures of student work:

As you can, see this activity definitely kept my students BUSY!

But, it kept them more than just busy.  It sparked great conversations and great thinking.  I did have to urge a few students to seek out a short cut because they were working each number individually.  But, most of my students found the short cut on their own.

Students did seem to gravitate toward referring to the numbers as "good" and "bad" instead of "happy" and "sad."

Things Students Said:

* Hasn't the color coding already been done for us on this worksheet?  (Oh, child.  Not coloring both the happy numbers and sad numbers is NOT going to fly.  Nice try, though.)

* Is this going to make a design?  (At least one student asked this each class period.  I think this is a result of doing so many logic puzzles before this.  I told them they would have to wait and see!)

* This is depressing.  So many sad numbers.  Why can't all the numbers be happy?

* When I started, I thought all the prime numbers were going to be sad.  But, I realized that wasn't the case when I started working.

* Since we are squaring the numbers, I wonder if there's a shortcut to determine if they are happy or sad by taking the square root.

* Oooh!  Changing the order of the digits doesn't actually change the problem.  If 19 is happy, 91 has to be happy.  (I'm sad to admit that I didn't find this shortcut.  This could have saved me some definite time!)

* With all the cancer there is in the world, why are mathematicians wasting their time studying happy and sad numbers?  They should be trying to find a cure for cancer!

This activity is a definite keeper!  I'm just trying to figure out where it would best fit into my school year.  Maybe as a beginning of year activity?


  1. I feel a moral obligation to point out...
    ...mathematicians _are_ trying to find a cure for cancer.

  2. Looks like fun! Printed it out for some summer math fun for my kids and me.