# Math Class



## Kevin (May 15, 2015)

I've looked all over the internet and YT to find out a short way to divide a mixed number into equal parts and all I find is how to divide one mixed number by another. I can do many in my head for example most of us who use mixed numbers a lot can do the math on 5 1/4 *÷* 3 = 1 3/4 easy peasy japaneasy. No paper or calculator needed.

But what about 9 11/16 *÷ *3? I need a formula to solve that and can't find it. I could have told you when I was in the 5th grade 7th grade college but that's been a while. The google calculator says the answer is 3.229 which I'm sure is right but I want to know how to do it when I'm not at a computer and don't have my phone. I know I have to convert to decimals first and I can do that, but after that I don't remember. I know I should be 90% there after going from fracs to dec but some reason I'm not ending up right. 

Math tutor please? Maybe we could have a volunteer that at least minored in math to teach a weekly math formula like Marc's QotW and Henry's WotW.

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## Tclem (May 15, 2015)

9 divided by 3 is 3
11 divided by 16 is .68 divided by 3 is .229 plus the original 3 is 3.229
So your calculator is right

Reactions: Thank You! 1


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## Tclem (May 15, 2015)

Tclem said:


> 9 divided by 3 is 3
> 11 divided by 16 is .68 divided by 3 is .229 plus the original 3 is 3.229
> So your calculator is right


What about that English professor @SENC

Reactions: Funny 1


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## Kevin (May 15, 2015)

Tclem said:


> 9 divided by 3 is 3
> 11 divided by 16 is .68 divided by 3 is .229 plus the original 3 is 3.229
> So your calculator is right



Damnit I always make things too hard. That was easy. 

.6875 though to make it all the way to 11/16.


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## Kevin (May 15, 2015)

Tclem said:


> What about that English professor @SENC



His hands are full and I'd prefer someone with a sense of humor. He's way too serious to be our math instructor.

Reactions: Funny 2


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## Tclem (May 15, 2015)

Kevin said:


> His hands are full and I'd prefer someone with a sense of humor. He's way too serious to be our math instructor.


Yes it would have been a two page lecture

Reactions: Agree 1 | Funny 3


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## TimR (May 15, 2015)

I know you're gonna hate this... but here goes. 
Long Division Wiki
It kinda depends on whether you want to leave in digital format, or need to reconvert to mixed. Me, I'd convert to digital, i.e 9.6875 since most precision rules and charts have conversions for sixteenth increments to digital. Then just do the long division on 9.6875 and get about 3.229, and if you want to convert the ".229" to fractional, just multiply by however fine you need to measure. If 16ths is good enough, multiply by 16 to get 3.6, or just under 4/16 (i.e 1/4"). Alternatively, multiply .229 by 32 to get 7.3 thirtyseconds...or a total of a little over 3 and 7/32.

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## Tclem (May 15, 2015)

TimR said:


> I know you're gonna hate this... but here goes.
> Long Division Wiki
> It kinda depends on whether you want to leave in digital format, or need to reconvert to mixed. Me, I'd convert to digital, i.e 9.6875 since most precision rules and charts have conversions for sixteenth increments to digital. Then just do the long division on 9.6875 and get about 3.229, and if you want to convert the ".229" to fractional, just multiply by however fine you need to measure. If 16ths is good enough, multiply by 16 to get 3.6, or just under 4/16 (i.e 1/4"). Alternatively, multiply .229 by 32 to get 7.3 thirtyseconds...or a total of a little over 3 and 7/32.


Ok senc jr. Lol

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## TimR (May 15, 2015)

Tclem said:


> Ok senc jr. Lol


It's a NC thang...

Reactions: Agree 1 | Funny 1


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## ripjack13 (May 15, 2015)



Reactions: Agree 1 | Funny 2


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## Schroedc (May 15, 2015)

@Kevin- Just get yourself one of these


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## TimR (May 15, 2015)

Schroedc said:


> @Kevin- Just get yourself one of these
> 
> View attachment 78446


Or one of these

Reactions: Like 1 | Funny 1


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## SENC (May 15, 2015)

Tclem said:


> 9 divided by 3 is 3
> 11 divided by 16 is .68 divided by 3 is .229 plus the original 3 is 3.229
> So your calculator is right


You didn't carry the naught.


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## ripjack13 (May 15, 2015)

Someone needs to invite Danica McKellar to be the resident math teacher....

Reactions: Agree 1


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## SENC (May 15, 2015)

Tclem said:


> What about that English professor @SENC


I would have liked to see a little more precision, but you showed your work so, overall, nice job.


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## Treecycle Hardwoods (May 15, 2015)

11/16 divided by 3 is the same as saying 11/16 divided by 48/16

to divide fractions you invert the second fraction and then multiply to it would look like this

11/16 X 16/48 reduce the fractions and it looks like this 11/1 X 1/48 = 11/48ths

11/48ths = .22916666666666 (the 6 will repeat)

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## ripjack13 (May 15, 2015)

Too many numbers here for me....I'm going home.

Reactions: Agree 2 | Funny 1


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## Kevin (May 15, 2015)



Reactions: Great Post 1 | Funny 7


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## justallan (May 15, 2015)

Like others, I just change things to a decimal point and go.
Divide the top number by the bottom number=====11 divided by 16=.6875
So you have 9.6875 divided by 3 is 3.229

Reactions: Like 1 | Agree 1


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## Kevin (May 15, 2015)

justallan said:


> Like others, I just change things to a decimal point and go.
> Divide the top number by the bottom number=====11 divided by 16=.6875
> So you have 9.6875 divided by 3 is 3.229



You and Tony get the apple. It's my preferred method too when I can remember it. I'll ask again next year month so don't make fun.

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## Treecycle Hardwoods (May 15, 2015)

Kevin said:


> You and Tony get the apple. It's my preferred method too when I can remember it. I'll ask again next year month so don't make fun.


WHAT?!?!?!?! I'll give ya an apple buddy!!!


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## Kevin (May 15, 2015)

Treecycle Hardwoods said:


> WHAT?!?!?!?! I'll give ya an apple buddy!!!



If you have one apple and give it to me, how many apples did Tony steal from Henry?

Reactions: Funny 3


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## Treecycle Hardwoods (May 15, 2015)

Kevin said:


> If you have one apple and give it to me, how many apples did Tony steal from Henry?


all of em!

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## Schroedc (May 15, 2015)

Kevin said:


> If you have one apple and give it to me, how many apples did Tony steal from Henry?



Thursday if the goat has on plaid socks.

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## justallan (May 15, 2015)

I surely agree on forgetting things. Being the smart (slightly egotistical) SOB that I am, I've tutored GED classes and the last one I did 4 years ago I found myself looking in the book to refresh myself. YUP, that's a real confidence builder for the folks your trying to help.

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## GeauxGameCalls (May 15, 2015)

Totally ignoring this thread. I just got tutored for three hours and took a test two days in a row.

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## Tclem (May 15, 2015)

Kevin said:


> If you have one apple and give it to me, how many apples did Tony steal from Henry?


Henry has pumpkins

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## SENC (May 15, 2015)

And big'uns.

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## Brink (May 15, 2015)

9-11/16 by 3?
16x3=48
11/48
3-11/48

Not much help on a yardstick


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## barry richardson (May 15, 2015)

Here's another technique; mark out the length, then with dividers I tweak them till till I can get there in 3 steps. Then measure the distance between points. Or use the red neck calculator; take a strip of paper cut to the length you want to dive, then fold in thirds..

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## justallan (May 15, 2015)

Here's what you do. You take a board 9 11/16", Write Hersheys Chocolate on it and toss it to 3 kids. I kid you not, there may be a black eye and a busted lip or so, BUT there WILL BE 3 equal parts!

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## ripjack13 (May 15, 2015)

Depends if they are related....
The oldest always got the bigger part, and moved smaller on down the line...
Unless the middle kid was fast runner. Then I would get the bigger part.
Chew and screw.....

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## kweinert (May 19, 2015)

Late to the party, but it depends on what you are using the result for.

As we know, keep the whole and fractional separate. So in this case 9 /3 = 3.

Now you have 11/16 Divide the 11 by 3 and you have 3 with 2/3 of a 16th left over. So we're at 3 3/16 with almost an entire 16th remaining - probably close enough to 1/4. If you need it more precise, measure it in 32nds. So 11/16 is 22/32. Divide 22 by 3 and you have 7/32 with 1/3 of a 32 left over. So it's 3 7/32. 64ths? 44/64, 44/3 = 14 with 2/3 of a 64th left over, so 3 15/64 would be pretty close. And so on.

Those are for if you're actually trying to measure something. For exact values you can convert to decimal as others have done, but unless you have a decimal measuring device you're going to have to convert back - right?


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## Kevin (May 19, 2015)

kweinert said:


> Late to the party, but it depends on what you are using the result for.



I guess I never said that did I? 

I'm using it to cut octagons. I use 2 different methods to do it and one of them demands dividing the blank into thirds both ways and I don't like resawing blanks down to the easiest divisible dimension lol.


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## kweinert (May 19, 2015)

Oh, then why measure at all?

Just take your tape measure and put one end on one side and a number divisible by 3 on the other side (for your 9 11/16 blanks I'd use 12) crossing diagonally. Then just put a tick mark at 4 and 8 and you've divided the board into thirds.

Right?

Reactions: Agree 1 | Way Cool 1


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## Kevin (May 19, 2015)

kweinert said:


> Oh, then why measure at all?
> 
> Just take your tape measure and put one end on one side and a number divisible by 3 on the other side (for your 9 11/16 blanks I'd use 12) crossing diagonally. Then just put a tick mark at 4 and 8 and you've divided the board into thirds.
> 
> Right?



I can't picture stuff like that you got to show me. I can't see how 4 and 8 are thirds of 9 11/16.


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## kweinert (May 19, 2015)

Take a look at the attached file. It's probably upside down but it should be readable.

I think.

Reactions: Thank You! 1


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## Kevin (May 19, 2015)

I can't open it even when I save it.


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## Kevin (May 19, 2015)

Okay I was able to open it, but it makes no sense at all to me. Your rule is not corner to corner nor along a side. It appears to just be thrown on top of the square randomly and the marks make no sense whatsoever to me. How are 3 & 6 equal divisibles of 9 11/16?


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## SENC (May 19, 2015)

Kevin said:


> I can't picture stuff like that you got to show me. I can't see how 4 and 8 are thirds of 9 11/16.


They aren't. They're thirds of 12. Kweinert's suggestion is a great one! You're measuring on the angle - whatever angle it takes to make the length easily divisible by 3.


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## Kevin (May 19, 2015)

Here's your image I did the work for you (again lol)


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## kweinert (May 19, 2015)

It's not random.

The 0 mark is on one side.

The 9 mark is on the other.

So, on a diagonal you're measuring 9" across the board (in your case it would be 0 and 12 but my paper can't go to 9 11/16 wide :) By putting a mark at 3 and 6 *on the diagonal* you're marking the 1/3 points of that diagonal. It doesn't have to be corner to corner, it just has to go from top to bottom (or left to right). It does have to cross the entire board. 

Trust me. If you take one of your blanks that you've measured and marked and take a ruler (or tape measure) and put the 0 on one side and the 12 on the other, the 4" and 8" marks on the ruler will line up with your measured lines.

If you needed to divide the board into 4ths in your case you'd put the marks on 3, 6, 9 (in the case of the above picture I'd change to 8" and mark 2,4,6 or 10" and mark 2.5, 5, 7.5)

The trick in doing this is to use a diagonal that's a multiple of the number of pieces you want to divide into that's larger than the width of what you want to divide.

In your case you want 3 pieces and your width is 9 11/16. The next higher multiple of 3 is 12. So you put the 0 on one side, the 12 on the other so you're spanning the entire width of the board and put your marks on the 4 and 8. You've now divided the line crossing your board into thirds. Now, using those marks draw lines through those marks that are parallel to the edges you just put the 0 and 12 on and you've divided the board into thirds.

In the case of the example the square is only 7 11/16. The next higher multiple of 3 is 9. So I put the ruler across the square with 0 on one side and 9 on the other then mark at 3 and 6. Drawing lines that are parallel to the top and bottom that pass through the points I just drew will split the square into thirds.

And of course the easiest thing to do is once you've done this once on a scrap piece that's the same size as your blank you just cut off one of those thirds and use it as a straight edge to mark all your blanks and never measure again. Presuming, of course, that you're doing multiples of the same size.

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## Mike Jones (May 19, 2015)

I think that there's an app for that.


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## Kevin (May 19, 2015)

kweinert said:


> The 0 mark is on one side.
> 
> The 9 mark is on the other.



Okay that's all it took . . . genius! Thank you!


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## Kevin (May 19, 2015)

Ken I didn't read past those two lines do I need to - is there other info in there or just trying to get through my thick skull? Pressed for time right now . . .


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## kweinert (May 19, 2015)

Just that the lines you draw through the marks need to be parallel to the sides you put the 0 and 12 on.

And a shortcut - do this on a scrap of the same size as your blanks, cut it out, use it for a straightedge and don't worry about measuring again (presuming your blanks are all the same size.)

Reactions: Thank You! 1


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