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Frisky Feline

Frisky Feline

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help

show your work


2.6 / 4.8 = .5416666


but I need the full show of how to do it. yea its for my kids school.

thanks
 
We'll see if this formats right. If it doesn't, I'll handwrite it and scan it.

Make your life easier, divide top and bottom by 2 first,

now the problem is 1.3 / 2.4 or same as 13/24 (think multiply top and bottom by 10)

So you set up
_______
24 ) 13.0

I put the ".0" after the 13 because 24 is too big - you can't get 24 out of 13. So you ask yourself how many times 24 goes into 130. You know 20x5 is 100, so that's a good start. 24x5 is 120. That's good because 130 - 120 leaves only 10. (10 is less than 24, so you know you didn't guess too low.

____.5
24 ) 13.00
-12 0
_____
1 0

Note you can always put more zeros at the end so you can keep working.

____.5
24 ) 13.00
-12 0
_____
1 00

Now ask yourself how many times 24 goes into 100. Answer is 4. Write the 4 on top, multiply 24x4=96. Write 96 below and subtract from 100


____.54
24 ) 13.00
-12 0
_____
1 00
- 96
_____
4

bring down another 0


____.54
24 ) 13.000
-12 0
_____
1 00
- 96
_____
40

24 into 40? It only goes once. Write 1 on top.



____.541
24 ) 13.000
-12 0
_____
1 00
- 96
_____
40

Then multiply 1x24=24 below and subtrace 40-24=16


____.541
24 ) 13.000
-12 0
_____
1 00
- 96
_____
40
-24
____
16


Bring down another 0

____.541
24 ) 13.000
-12 0
_____
1 00
- 96
_____
40
-24
____
160

and ask how many times 24 goes into 160. Answer 6 because 24 x 6 = 144. Write 6 on top, 144 below, subtract.


____.5416
24 ) 13.000
-12 0
_____
1 00
- 96
_____
40
-24
____
160
-144
____
16

bring down another 0 and you start to see that you'll keep getting 160 over and over, you'll keep needing a 6 on top again and again forevern and so you have a repeating decimal.

____.5416666...
24 ) 13.0000
-12 0
_____
1 00
- 96
_____
40
-24
____
160
-144
____
160
-144
_____
160
-144
_____
etc


So the answer really is .541666666666666666666666666666 etc

_
You can write it as .5416
 
Ok, here's the scan. Please especially note the final answer - the bar above (like everything else) got moved over to the left. It should be over the last digit (6).

The comments I typed up are still ok. The numbers just don't line up vertically.

amylynne-albums-what-picture6171-divide.jpg
 
no you lost me! I don't get it what you said 24??? how did it gets 24 instead of 2.6.

2.6 / 4.8 =

phone camera can do the trick to put it here.
 
I understand division by 2. but I never heard of it before. I m playing with number right now. thanks for your patience with me.
 
Hope you can read my scratch. The first thing to remember is you want a whole number in the divisor (the number you are dividing by). So you move the decimal 1 place to the right to change it from 4.6 to 46. And anything you do to the divisor, you have to do to the numerator (the number getting divided) so 2.6 becomes 26.

Notice how I make the digits in the quotient (the result of the long division) line up with the bottom. This makes it easy to track where the decimal goes. Since 46 doesn't go into 26 evenly, the first number you put is 0 and follow it with the decimal point. When you're working with decimals and you are to the right of the decimal, you can add as many 0's to the end as you want. Meaning that 1.1 = 1.10 = 1.100 just as 1 = 01 = 001.

Once you get to the 6, the remainder keeps repeating; this is shown in the quotient by putting a bar over the digits that repeat.

soulchill-albums-public-picture6172-division.jpg
 
If you had to divide 600 by 300 (300/600) you can make your life easier and just divide 3/6, right? That means you cancelled 100, that is, you divided the top and bottom both by 100. Then you have a simpler problem.

That's what I did with your problem. First I divided top and bottom by 2.

So the top became 1.3 and the bottom became 2.4

New problem 1.3/2.4

But I don't want to work with decimals like that, so I multiply top and bottom by 10. Or you can think of moving the decimal one place to the right. That's ok as long as you do the exact same thing on top and bottom:

13/24

You can do the original problem, it turns out the same. I can write it up if you want
 
She "simplified" the fraction before doing the division by dividing the numerator and denominator by a common denominator (2). My oldest still has issues with this. ;)
 
Soulchill wrote it up without dividing by 2, so I won't bother to do that. But I can still talk to you about details if you want. No problem about patience:)
 
soulchill said:
Hope you can read my scratch. The first thing to remember is you want a whole number in the divisor (the number you are dividing by). So you move the decimal 1 place to the right to change it from 4.6 to 46. And anything you do to the divisor, you have to do to the numerator (the number getting divided) so 2.6 becomes 26.

Notice how I make the digits in the quotient (the result of the long division) line up with the bottom. This makes it easy to track where the decimal goes. Since 46 doesn't go into 26 evenly, the first number you put is 0 and follow it with the decimal point. When you're working with decimals and you are to the right of the decimal, you can add as many 0's to the end as you want. Meaning that 1.1 = 1.10 = 1.100 just as 1 = 01 = 001.

Once you get to the 6, the remainder keeps repeating; this is shown in the quotient by putting a bar over the digits that repeat.

soulchill-albums-public-picture6172-division.jpg
Click to expand...

OH I didn't put zero before the demical. That's where I got stuck. let me try it because your method is the same way what I did in the past. I never heard of two division what amylynn did show it.
 
oh I put the wrong numbers in order 2.6/4.8 but you all put 4.8 / 2.6 I don't know why I forget .


thank you both, amylynn I agree its easier that way but I have never done it before. its new to me now. LOL

soul, thanks it sound slike you are the same age as I am. 40's??? hee hee
 
Whichever way you like is cool. That trick is nice if the numbers get unmanageable and you notice you can make them simpler.
 
oh I hate the whole "show your work!" stuff. The algebra teacher I had for intermediate algebra at college in 2007 insisted we show our work EVERY single time! uuuugggghhhh. I so much like the online math better, no need to show the work, just plug in your answers and hope you get them right so you can pass each module test until you're done with the course!
 
cdmeggers said:
oh I hate the whole "show your work!" stuff. The algebra teacher I had for intermediate algebra at college in 2007 insisted we show our work EVERY single time! uuuugggghhhh. I so much like the online math better, no need to show the work, just plug in your answers and hope you get them right so you can pass each module test until you're done with the course!
Click to expand...

When I taught, the work was pretty much the only thing I cared about. You could make a little mistake and get the wrong answer and that was never too big a deal to me. But if your work is good, then I know you've understood the material, which is the real value in a course. Someone can guess and sometimes get a right answer, which isn't worth anything to me.

I remember one time I was teaching a calc class and I had a student bring a quiz back to me that I'd graded. Everything he'd done on it was wrong, and on the first problem, he'd gotten an answer of -1. The actual answer was 1, and he felt he should get partial credit. I told him "I'm not grading you on how close your pencil got to the right answer, I'm grading you on how close your mind did."

That seemed to shake him up a bit.
 
I can understand having to show you work for some of the problems, but for every single one when the concept is the same or similar? Sometimes I can't even explain how I would come up with some of the answers and can't show how I came up with the answer. That's another issue for me haha.
 
It's important to show the work because the instructor also needs to see at what point the mistake was made when there is an error. They can't help the student if they don't know where the mistake was made.

I find writing down the steps also helps to make the process more clear in my mind.

I use a calculator now for convenience but I'm very glad that I didn't have one when I was learning math.
 
Sometimes I'll be working privately with a student and they'll whip out their calculator. I take it out of their hands and put it out of their reach. They look like someone just took their IV away. Or their morphine drip. Then I'll walk them through whatever it was - so often it's something that really benefits the to learn how to think through, and having that shortcut there so conveniently does them a huge disservice. If there's some horrible ugly computation that isn't remotely instructional, I'll let them use the machine to crunch some numbers, but I don't want them walking away from a session not knowing how to do basic things that were part of the material we were working on.
 
cdmeggers said:
I can understand having to show you work for some of the problems, but for every single one when the concept is the same or similar?
Click to expand...

It depends on the subject and it depends on the student. If it's an advanced college math course I'm not going to expect to see every polynomial multiplication written out in steps. I expect students to do some things in their heads once they've done (or should have done) them a million times.

But in an assignment that is focused on a particular skill, I want to see the details of the students' mastery of that skill. So in a basic algebra class I'd want to see more of the algebra.

But you get a sense of students too. Someone who is struggling with the material and is missing the concept half the time needs to write more of their work out, for their own benefit and so I can see how they're doing. Then I'll have students I've worked with enough to know they already have those skills down like the back of their hand, and I don't need to see as much detail from them.

If you clearly progress from the first situation to the second in the course of one assignment, I can see what you're saying - show your work until it's clear you've got it and then leave out the parts you can do in your head. Sometimes students feel like they get it a little prematurely, and could use a little more practice than they realize, but that said, yeah, I'm not looking to abuse people for sport.
 
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