Day: October 5, 2017


Kids today have it so easy.

Back in my day, when we wanted a computer to solve a problem, we had to write a piece of code to make it happen.

Now, there’s an app for everything, it seems!

I had a great deja vu moment the other day.  I found this resource.

Prime Factorization Calculator

It’s based upon a simple premise.  Ask the user to enter a number, any number, and it will return all of the factors of the number that are prime numbers.

So, 11 should return just 11 since 11 is a prime itself.

And, 12 should return 2, 2, and 3.

Simple enough, right?

How about a number that’s not quite that solved mentally, like say 777.  That’s when it gets interesting and beyond the problem solving ability of mere mortals.

Screenshot 2017-10-04 at 07.05.27

Of course, you (as I did) will do a little mental mathematics to check this.  Or, perhaps you took the easy way out to check it with a calculator.

What particularly intrigued me was that this was a problem that I did in high school and later reused it in my own computer science classes.  It’s not a trivial problem for solution but there’s huge satisfaction when you get it to work.  I do recall a modification making it less open by indicating that the number input has to be equal to or less than 1000.

It also opens one of those teachable moments since 1 is not included.  Hey, isn’t 1 a prime number?  Great discussion ensued.

I still think that it’s a wonderful problem for students to design an algorithm and generate a computer solution.

For those students and others, there are all kinds of functionality at this resource.

Like they say, today there’s an app for darn near everything.


OTR Links 10/05/2017

Posted from Diigo. The rest of my favorite links are here.