The Purpose of PowersDate: 07/30/2002 at 11:36:08 From: Laura Subject: Powers I don't understand the whole purpose of powers, what they do, and how to use them. Help me please, Dr. Math. Date: 07/30/2002 at 12:19:38 From: Doctor Peterson Subject: Re: Powers Hi, Laura. You can find a lot of help with powers in the Dr. Math archives: Middle School Exponents http://mathforum.org/library/drmath/sets/mid_exponents.html I hope you will look through some of the answers that interest you, and then write back with any more specific questions you have. This might be a good place to start: What is an exponent? http://mathforum.org/library/drmath/view/58212.html To briefly answer your question about the purpose of powers, let's go back a couple of years and pretend you only know about addition, and not multiplication. Suppose you've heard that multiplication is really hard, and you ask me why it is needed. Can you think of some answers I might give? One answer to that is that multiplication lets you state problems that would be very big if you just used addition. I can say '17 times 3' where you would have to say '3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3'. Another answer is that multiplication gives me a way to calculate big sums more quickly. To multiply 17*3, I just have to know 1*3=3 and 7*3=21, rather than having to add up 17 3's. So multiplication saves a lot of time. That's exactly what powers (or exponents) do for you. Just as multiplication (in its simplest form) is just repeated addition, a power is just a repeated multiplication. So exponents allow me to talk about big problems like 100*100*100*100*100*100*100 by just saying 7 100 Once I know this terminology, I can learn the rules of working with exponents, so they let me solve problems more quickly. There's a lot more you can do down the road using exponents (such as in algebra, where they become very important), but this gives you an idea how useful they can be. If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/ |
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