Author Topic: Calling Marv Klotz (Math calculati (Read 7862 times)

gbritnell · « **on:** December 30, 2012, 10:19:34 PM »

My math is a little rusty in the area of order of operations. I know that anything in parenthesis has to be performed first and I know that after everything is performed I have to find the square root but I don't know what the 1- means and should it come before squaring. Equation attached.
gbritnell

stevehuckss396 · « **Reply #1 on:** December 30, 2012, 10:30:09 PM »

Quote from: gbritnell on December 30, 2012, 10:19:34 PM

My math is a little rusty in the area of order of operations. I know that anything in parenthesis has to be performed first and I know that after everything is performed I have to find the square root but I don't know what the 1- means and should it come before squaring. Equation attached.
gbritnell

I believe it is just that 1 minus

1 minus all the hocus pocus to the right of it.

stevehuckss396 · « **Reply #2 on:** December 30, 2012, 10:35:44 PM »

A = 2.77/12.92

B = A^2

C = 1-B

D = Sqrt(C)

D = 0.97674664063

Being this is a one question test, I got an "A" or an "F"

What did I get?

mklotz · « **Reply #3 on:** December 30, 2012, 10:50:21 PM »

Yup, Steve nailed it. Give him an 'A'.

gbritnell · « **Reply #4 on:** December 31, 2012, 01:14:37 AM »

Thanks Steve and Marv but I still can't get it to match the sample calculation. This is from Kozo Hiraoka's skew gear calculations. I'm attaching the complete equation.
gbritnell

zeeprogrammer · « **Reply #5 on:** December 31, 2012, 01:21:51 AM »

Multiply the 1.7 * .844 first then add.

stevehuckss396 · « **Reply #6 on:** December 31, 2012, 01:54:13 AM »

A = 21.82 + 2 * .85 * C0s(32.41) * 0.97674664063

A = 21.82 + 1.7 * Cos(32.41) * 0.97674664063

A = 21.82 + 1.435 * 0.97674664063

A = 21.82 + 1.401

A = 23.221

steamer · « **Reply #7 on:** December 31, 2012, 02:16:38 AM »

Ahhh Steve beat me too it....

gbritnell · « **Reply #8 on:** December 31, 2012, 03:11:24 AM »

Thanks guys,
It's great to have all the help. So all multiplication and division would be calculated before addition or subtraction?
gbritnell

steamer · « **Reply #9 on:** December 31, 2012, 03:19:28 AM »

The order is

Exponents and Roots
Multiplication and Division
Addition and Subtraction

Dave

Tin Falcon · « **Reply #10 on:** December 31, 2012, 04:00:14 PM »

Please Excuse My Dear Aunt sally
Parentheses, Exponents (and roots), Multiplication, division Addition, subtraction
tin

gbritnell · « **Reply #11 on:** December 31, 2012, 08:28:11 PM »

Thanks Tin,
I went through all the calculations and their sample answers and they all came out correct. It's easy when you know how! I have been plugging my own numbers it but it's taking time. There's almost 3 pages of calculations to do.
Oh well, I have all winter to get this differential made.
gbritnell

mklotz · « **Reply #12 on:** December 31, 2012, 09:42:12 PM »

George,

If you're doing multiple calculations with the same formulae but different numbers, you may want to consider something like a programmable calculator or a spreadsheet.

Once you've got the spreadsheet set up and operating correctly as proved by your sample calculations, plugging in your own numbers becomes a doodle and you're assured that no errors were made in the calculation (as is possible if done by a human). Especially when doing design work, the ability to repeat calcs many times with slightly different numbers becomes a real time saver.

Moreover, if you ever do this again in the future, the spreadsheet implementation will remember perfectly how to do it - something most humans can't do.

Jo · « **Reply #13 on:** December 31, 2012, 10:05:42 PM »

Quote from: mklotz on December 31, 2012, 09:42:12 PM

Moreover, if you ever do this again in the future, the spreadsheet implementation will remember perfectly how to do it - something most humans can't do.

Or repeat exactly the same miss-calculation perfectly every time.

Jo

mklotz · « **Reply #14 on:** December 31, 2012, 10:10:47 PM »

Quote from: Jo on December 31, 2012, 10:05:42 PM

Quote from: mklotz on December 31, 2012, 09:42:12 PM

Moreover, if you ever do this again in the future, the spreadsheet implementation will remember perfectly how to do it - something most humans can't do.

Or repeat exactly the same miss-calculation perfectly every time.

Jo

I guess you missed the part where I wrote,

"Once you've got the spreadsheet set up and operating correctly as proved by your sample calculations...."

steamer · « **Reply #15 on:** December 31, 2012, 10:20:24 PM »

I can do this....provided its not too much....George...can you scan your calcs?....or perhaps the article....I have it but I'll have to dig it out.....

Dave

steamer · « **Reply #16 on:** December 31, 2012, 10:21:54 PM »

Unless Marv....you would like to do this oh Maestro....

Dave

mklotz · « **Reply #17 on:** December 31, 2012, 10:29:09 PM »

Quote from: steamer on December 31, 2012, 10:21:54 PM

Unless Marv....you would like to do this oh Maestro....

Dave

I don't do spreadsheets. I don't have a spreadsheet program and, if I did, I wouldn't know how to use it. It's an ignorance I treasure (along with my inability to recognize pop music stars and comprehend football).

steamer · « **Reply #18 on:** December 31, 2012, 10:31:22 PM »

OK Marv.....I'll do it....George...if you want one, I'll do it

Send me the article stuff and we'll go from there.....its going to be a quiet night anyway....

Dave

Maryak · « **Reply #19 on:** January 01, 2013, 02:37:22 AM »

George,

BODMAS or BOMDAS oldies but goodies

Brackets, then
Of, then
Multiplication/Division, then
Addition/Subtraction.

Dredged from the depths of my high school years

Hope this helps

Best Regards
Bob

gbritnell · « **Reply #20 on:** January 01, 2013, 03:01:15 AM »

Hi Dave,
I got your email before I read your response here. I could scan the pages and send them to you but there are 3 of them for the gear and tooth calculations so you might be asking for more than you're bargaining for.
Let me know,
Thanks,
George

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Author Topic: Calling Marv Klotz (Math calculati (Read 7862 times)