Can some show how this is done.....
- Thread starter dnorr
- Start date
tkhunny said:
The answer key does it a little differently.....
The sales tax is a certain percentage of the price, so I first have to figure what the actual tax was. The tax was:
7.61 – 6.95 = 0.66
Then (the sales tax) is (some percentage) of (the price), or, in mathematical terms:
0.66 = (x)(6.95)
Solving for x, I get:
0.66 ÷ 6.95 = x = 0.094964028... = 9.4964028...%
The sales tax rate is 9.5%.
The trouble that I'm having is doing this in long division (can't use calc on test) ???
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0.66 / 6.95dnorr said:
You clearly have missed some arithmetic lessons in your past.....
0.66 divided by 6.95 should be set up THIS way for long division (note...you are dividing BY 6.95, so that goes "outside" the long division "box")
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6.95 ) 0.66it would be nicer if the divisor (the number we are dividing BY) was a whole number. So, let's multiply both divisor and dividend (the number we are dividing INTO) by 100. This will move the decimal point two places to the right in each number, making the number we are dividing by 695....a whole number.
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695 ) 66Notice that the number we are dividing into (66) is a little less than 1/10 of 695, so we should expect an answer that is a bit less than 1/10. 1/10 written as a decimal is 0.1, so we would be looking for an answer less than 0.1, but close to it. An answer of 0.09 might be "in the ballpark" as an estimate.
Ok....
now it is time for you to do some research and practice on long division. A search on Google for "lessons on long division involving decimals" produced a long list of websites devoted to this subject. Included are a number of "step-by-step" video lessons, which you may find useful. Here is one of them:
http://www.youtube.com/watch?v=UiB1pB_5 ... ure=relmfu
There is no EASY way to do long division without a calculator....if we KNEW of one, we'd surely have told you about it by now. So...please don't ask again. DO some research and practice.
D
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dnorr said:
Mrspi said:
Why do some of you come off with such an attitude? Are you adults or kids? I’m an adult who’s returned back to school after many years. I haven’t done long division since grade school. I’ve used a calculator since high school. If you’re going to help some one, help them!!!.....DON’T insult them because you feel that you know a little more about the subject. I’m sure I would draw rings around you in my profession. Let’s be fair here.....
"teaching" long division "properly" requires classroom environment; blackboard and the likes...
NOT available at sites like this one; try other "help" sites and you'll get same reply...
This will give you loads of sites to help you:
http://www.google.ca/#hl=en&biw=1020&bi ... fb28fe07a2
Good luck :idea:
NOT available at sites like this one; try other "help" sites and you'll get same reply...
This will give you loads of sites to help you:
http://www.google.ca/#hl=en&biw=1020&bi ... fb28fe07a2
Good luck :idea:
Denis said:
I'm o.k. with basic long division. The trouble that I'm having is with more complex long division, like dividing numbers with decimals and small numbers divided by large numbers, etc.....
0.66 ÷ 6.95
1.96 ÷ 14.89
3569 ÷ 56
98657 ÷ 486
18.23 ÷ 124.89
That sort of thing. Tried googling but not a lot dealing with this. If you know of any websites that deal with this please let me know. Thanks.
Denis said:
I'm not big on "PREACHING"!! Besides, that still does not address the question. Removing the decimals is only part of the answer. And what about dividing smaller numbers by larger numbers? So far I've found three or four different ways that people are doing this. There is no cut and dry method. Thanks.
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Okay, forget the preaching and start practicing. Develop a method that works for you. Think back to the first guy who ever did long division. If he was smarter than you or I, it probably wasn't by much. Nevertheless, he figured it out. This is what is required. Figure it out.
tkhunny
Evangelist of Practice and Hard Work
tkhunny
Evangelist of Practice and Hard Work
Remember this, too....
division and multiplication are VERY CLOSELY related.
If a divided by b = c, then it MUST BE TRUE that b*c = a.
If 10 / 2 = 5, then it MUST BE TRUE that 2*5 = 10.
If you are trying to divide 0.66 by 6.95, you can determine whether your answer is close or not by using this idea.
Suppose you say "I think that 0.66 divided by 6.95 is 10." If that's true, it must also be true that 6.95 * 10 = 0.66. But, if you do the multiplication, you get 6.95* 10 = 69.5. That's definitely NOT 0.66...in fact, it's WAY too big!!
So...maybe you should try something MUCH smaller than 10. How about 1? Could it be true that 0.66 divided by 6.95 = 1? Let's see....if that's the correct answer to the division, then 6.95 * 1 = 0.66. But wait...6.95 * 1 is 6.95. And 6.95 is surely not equal to 0.66. It's still too big.
We need to try something smaller, then. How about 0.1?
Suppose 0.66 divided by 6.95 = 0.1. If that's true, then 0.1 * 6.95 = 0.66. But, when you do the multiplication, you find that 0.1 * 6.95 = 0.695. That's NOT equal to 0.66.....but we are sure getting pretty close!
So, try something just a little bit smaller than 0.1....
By repeating this process, you can get an answer to the division that will get you as close as you want to be to 0.66 when you check.
I KNOW this is "more work" than the long division process that most students learn in elementary school. But...it's an alternative approach that may help you realize that there is something to be said in favor of an algorithm that may SEEM mysterious, but which produces nice results in a minimum number of steps.
division and multiplication are VERY CLOSELY related.
If a divided by b = c, then it MUST BE TRUE that b*c = a.
If 10 / 2 = 5, then it MUST BE TRUE that 2*5 = 10.
If you are trying to divide 0.66 by 6.95, you can determine whether your answer is close or not by using this idea.
Suppose you say "I think that 0.66 divided by 6.95 is 10." If that's true, it must also be true that 6.95 * 10 = 0.66. But, if you do the multiplication, you get 6.95* 10 = 69.5. That's definitely NOT 0.66...in fact, it's WAY too big!!
So...maybe you should try something MUCH smaller than 10. How about 1? Could it be true that 0.66 divided by 6.95 = 1? Let's see....if that's the correct answer to the division, then 6.95 * 1 = 0.66. But wait...6.95 * 1 is 6.95. And 6.95 is surely not equal to 0.66. It's still too big.
We need to try something smaller, then. How about 0.1?
Suppose 0.66 divided by 6.95 = 0.1. If that's true, then 0.1 * 6.95 = 0.66. But, when you do the multiplication, you find that 0.1 * 6.95 = 0.695. That's NOT equal to 0.66.....but we are sure getting pretty close!
So, try something just a little bit smaller than 0.1....
By repeating this process, you can get an answer to the division that will get you as close as you want to be to 0.66 when you check.
I KNOW this is "more work" than the long division process that most students learn in elementary school. But...it's an alternative approach that may help you realize that there is something to be said in favor of an algorithm that may SEEM mysterious, but which produces nice results in a minimum number of steps.