It’s already mid-week, yet I feel as though the week just started. I have much to do tomorrow at work in advance of a weekend event and I’m not sure I’ll have enough time to finish what I need to finish. This means I’ll have to go into efficiency overdrive and a state of extreme focus. We’ll see if the day will allow for this.

I just got off the phone with a good friend.

Daughter is practicing flute.

Hubby is chatting on an online forum. He sent me a paper via email and I need to go print it.

Young Son Number Two is watching House, which he has become addicted to over the past couple of weeks.

Earlier this evening, I helped Young Son with factoring prime numbers. I LOVE factoring prime numbers, figuring out what prime numbers are contained within a larger number. It’s one of the few things I enjoyed about pre-algebra and because I enjoyed it, I remembered the process. Young Son doesn’t care for factoring primes because it takes too much room on the paper to draw the factoring tree. The factoring tree is part of what makes finding the primes so interesting. That, and the fact that you can’t break the primes into further multiples of whole numbers. Prime numbers are attractive for their prime-ness.

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Erin G

said:I can relate, Mary. I’m not in love with factoring prime numbers. But I ADORE diagramming sentences. Mmmm.

Jody

said:Numbers make me shudder and I have no idea how to diagram a sentence? Good to talk to you Mary, I hope your day was super focused and you got done everything you needed:)

woowooteacup

said:I was super focused and got a few things done, but not everything, so I’ll just have to make do for the time being.

You know, I’m trying to remember whether I had to diagram sentences in high school. If I did, it obviously wasn’t memorable enough. Sheesh!

Amy Hunter

said:I had to diagram sentences in 9th grade English, although I don’t remember how to do it. But I don’t remember anything about factoring primes. If it was taught, it wasn’t with a tree. I do remember learning about prime numbers, though.

Rianna

said:Did you know that 0! is 1? I didn’t until I went to work today…

woowooteacup

said:Huh, Rianna? Care to explain?

Erin G

said:yeah I learned that in pre-calc. Zero doesn’t fit into normal factorial equations (5!= 1x2x3x4x5, etc) very well, so you have think about it like this:

Since 4! is really 1x2x3x4 (24), and 3! is 1x2x3 ( 6), you can rewrite that by saying that 3! is really 4! divided by 4… and so on.

Therefore, 0! is 1! divided by 1. Which is 1.

Make sense?

woowooteacup

said:I did not learn that in school, but then I didn’t take pre-calc, so that’d be why. Your explanation makes a little sense to me. It’s got something to do with that exclamation point, right? It’s a placeholder, sort of like “x” in algebra.

Erin G

said:no, the exclamation point means “factorial” – or “multiply this number times everything under this number.”

4! (4 factorial) is 4x3x2x1 =24.

So if you want to use a place holder, then:

x!= (x+1)!/(x+1)

0!= 1!/1… which is 1.

Why they chose an exclamation point, I do not know. A math person I am not. 🙂

woowooteacup

said:Ah! Makes sense now. So, then, what’s the use of knowing this, other than to know that in at least one instance 0! is 1?

Erin G

said:no use at all. only in math-dork world is this useful. which means you and I can get back to our appreciation of prime numbers and diagramming sentences and live in peace. a peace with no factorials. 🙂

Erin!