Life this Week -Scientific Notation

Life at our house this week....hmmmm, very busy. When I haven't been consumed with the normal everyday happenings (cleaning, cooking, homeschooling) this week, I've been trying to figure out Scientific Notation and Significant Figures to help my newphew Johnathan. It seems that he isn't doing as 'ok' in public school as his parents have said he was for the past few months. Who is? Public school is a rat race and all of us parents want it to be ok, but it's usually not ok. Parents are afraid to admit when a kid isn't doing ok for fear of everyone thinking that it's a reflection on the kid's intelligence or the parent's ability to see to it that they are getting an education. Neither of those are true though. It is the SCHOOL that hasn't done it's job.....and when you have a kid who is making bad grades, it's the SCHOOL'S FAULT, and when you have one who is making good grades....you better make sure you see the work so you'll know they are actually EARNING those grades and not just slipping through the system. At any rate, I got a call from his mother asking me if I could possibly help him with some Science. He had missed a whole week of school the week before (medical reasons) and had a TON of make-up work to do in his Science class and they were stumped as to how to do some stuff. I thought "sure, it's Science, how hard could it be?" Not sure why they asked me to help, I mean, yeah, I'm a HOMESCHOOL teacher, which means I'm intelligent enough to teach my own children and I know where to find answers when I don't quite understand things myself, but I am by no means a TEACHER with a degree. I learn a lot as my kids learn.

So, we make plans for the next evening for them to come over. Turns out, it's PHYSICAL SCIENCE. Not just Science. And the 'math problems' they were having so much trouble understanding were 'Equations in Scientific Notation'. Big difference, at least to me. Math to me is simple addition, subtraction, multiplication, division, fractions, etc. Those of you who know what Scientific Equation is know what I'm talking about. It's anything but simple (except maybe to the geniuses of the world). So, I had to start from the beginning myself to learn this stuff. Crash course in both Algebra and Scientific Notation. Thank God for the Internet. There are a lot of good sites out there that explain things really well, so I was able to learn a lot fast, and then came the page with adding in Scientific Notation. You'd think it would be simple:

(2.34 X 10^12) + (4.473 X 10^15) =?

Simple, huh? Just add the decimal numbers...and then...uh, ok, what about the 12 and the 15? Hmmmm, do I add them together maybe? Yeah, that's gotta be it. WRONG!! Cause the next part of the example said:

(0.00234 + 4.473) X 10^15 = ?

Ok, where did those zeros come from? WHY did the numbers change? Why does the 4.473 not change? And where did the 12 go in the 10^12? AND, why does THEIR answer have only three digits when mine has a bajillion? Believe me, I was sooooo confused and couldn't find the answer to these questions anywhere. I even sent out an SOS to my homeschool group in the hopes that a veteran homeschooler might have been there and done that and could enlighten me. Instead, I think I scared the one's to death that have younger kids because they thought about having to TEACH that in the upper grades. LOL (sorry about that guys, didn't mean to cause any coronaries there).

At any rate, I worked at it until I figured out the answer to those questions on my own, comparing my thoughts and mental notes to those of similar equations on some help sites. None of them gave an explanation.....but I'm that kind of person. I WILL eventually FIND THE ANSWER or figure it out myself. Just in case you're curious now...

The 10^12 goes away...because you use the exponent with the highest power, which is 10^15 for both addends. Hence, the addition equation that simply has the addends in parentheses and then the one X 10^15 =? at the end of it. The number 2.34 changed to 0.00234 because the difference between the 12 and the 15 (exponents) is 3, so you add that many zeros to that number so the value doesn't change, and the decimal point always goes to the right of the first digit. The addend with the exponent you used stays the same, it's value doesn't change. So, add those addends together, and you get
4.47534. Ok, but THEIR answer says 4.48. Again, confusion. Then I did find the answer to that one.....this is where 'significant figures' comes into play. Your answer has to have the same amount of significant figures (fancy terminology for 'digits') as the addend with the LEAST amount of figures in your original equation. In this case, it is 3 digits (2.34 is the one with the least), so your answer will have to be rounded to 3 digits and the decimal, again, is always placed to the right of the first digit. DONE.

I think I'm writing about this because my own kids will more than likely be doing Physical Science at some point (they just HAVE to now, so I can show off what I learned LOL).

I was able to help my nephew for the moment. Herrrrre I come to save the dayyyyyy!! LOL We'll see what happens this week. Stay tuned. LOL I should write a book when we get through this course called "Physical Science for Blondes". Oops. I'm sorry. That's politically incorrect. "Tips for the Physical Science Challenged"? BTW, don't get offended, I am blonde myself. Hee hee. If you're blonde, when I make fun of you, I'm making fun of me. :o)

What I WILL do though, is post some links to the sites where I found lots of goodies and help......math, scientific notation, algebra.....check the links called 'Great Homeschool Helps I've Found'.

So, that's all for today folks. Yep, see why I don't post but once a week? I post enough in one post for a week's worth of reading. :o) Stay tuned though, I might get a wild hair and write some more this week!!!