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• gonfission 2,246 Posts

  Mon, Aug 21 2017 7:01 PM

  Quibble away mkg  Good term.

  It's an algebraic test. As YJ said you do the multiplication first

  Either 10 x 2 + 1 = 21

  or 2 x 10 + 1 = 21, as you pointed out in two of your four possibilities

  One would never do the 1 + 10 = 11 x 2 = 22 or

  1 + 2 = 3 x 10 = 30

  Should be represented as 1 + (2 x 10) = 21 to be correct in algebraic form.

  Always perform the parenthesis task first to a formula. Now that's what I remember, it very well could have changed since I was schooling.

  Good quibble

  Edit: mkg, I looked at your post again, and knowing the "OOO" you are & alosso are correct.

  Knowing that there should be parenthesis but not seeing them does not take away from your notation.

  I bow to you quibble prowess, and stand corrected

  Thank you

   

• phred952 2,714 Posts

  Mon, Aug 21 2017 9:09 PM

  Joe,

  I am sorry to hear today was a bad day as far as our social security went.  Perhaps you will be given a better one tomorrow.  In any case we do appreciate it.

  Thanks Mate,

  Jeff

• Jimbog1964 8,378 Posts

  Mon, Aug 21 2017 9:53 PM

  YankeeJim:

  alosso:

  he who shows "22" should show the equation (for my simple mind to understand).

  He's not discounting the single boot, he's treating it like Jimbog did or didn't follow MDAS.

  p.s., I think your 21 is the right answer. I was all wet in the thinking.  :-(

  Not even sure they had that order of ops when I was a kid? 

  Fun exercise and my assumptions I suspected may not be right.  I did actually do well in economics strangely at business exam level..I don't remember that kind of test:)..I do remember well even back then there really is no exact science to any of it - Why we have left v right largely.

  Now the that MDAS is mentioned I do vaguely remember reading it when helping with the kids homework some time ago - vaguely.

  Was fun though.

  And yes those German people.......The British car industry descended into heaters that never worked, and lights that failed.  Been OK (maybe just) if the parts department was not also usually on strike for ages........Enter Japanese cars which actually worked all winter long, and of course, the over-engineered top of the range perfections from Germany just kept selling. Still great cars.  The once great British car industry simply ceased to exist.

• alosso 21,072 Posts

  Mon, Aug 21 2017 10:20 PM

  alosso:

  1 + 10 x 2 = 21

  I chose this display from the order of the symbols, just to be clear what is what. And, of course, "Punktrechnung geht vor Strichrechnung" in mind from grammar school (probably equivalent to MDAS).

  OTOH, this wee example is not comparable to scientific statistics. Listen to "Street Maths", a TEDx talk to see what everyday people need.

  @gonfisson: As for Power Ball, take

  1	2	3	4	5	+	26
  6	7	8	9	10	+	25
  11	12	13	14	15	+	24
  16	17	18	19	20	+	23
  21	22	23	24	25	+	22
  26	27	28	29	30	+	21
  31	32	33	34	35	+	20
  36	37	38	39	40	+	19
  41	42	43	44	45	+	18
  46	47	48	49	50	+	17

  Your rake is 10%. Air fare and other expenses are on you, and 1 $ should be the minimum for me. You're welcome in NUE for some yummy beer and sausages + sightseeing + real golf.

• drmoose 3,542 Posts

  Tue, Aug 22 2017 4:26 AM

  Late to the party again, but, even after reading all the explanations. MDAS aside, I believe a case can be made for 22 to also be a correct answer. Just because the parentheses are implied, does not mean they in fact exist. Thus, we process information from left to right, not from the middle out, making 22 the logical answer.

  1+10 x2 = 22

  1+ (10 x 2 ) = 21

  Doc :)

• YankeeJim 25,827 Posts

  Tue, Aug 22 2017 5:16 AM

  drmoose:

  . MDAS aside

  You can't just toss a math rule out to make a case. 

• drmoose 3,542 Posts

  Tue, Aug 22 2017 5:54 AM

  Ah, Jim,  I most certainly can, lol ( see edited post ). In the absence of the parentheses the correct answer is 22. As stated, we process information from left to right, not from the middle out. Besides, we all know rules are made to be broken .

  Doc :

  Here's an example.

  Times are tough and you're down to your last sleeve of balls (1). You hit the lottery and decide to splurge buying ten more sleeves from the pro shop( +10) I challenge you to a match play game where the loser agrees to double the winners inventory of balls (x2). You, of course being the better player, win. Do I pay you 21 sleeves or, 22 ?

• mkg335 5,491 Posts

  Tue, Aug 22 2017 6:31 AM

  Doesn't matter about parentheses, Doc...say it with me:  OOO baby baby.

  (Smokey Robinson got it right)

  ;-)

• Jimbog1964 8,378 Posts

  Tue, Aug 22 2017 6:32 AM

  According to an article by Lawrence, it's just an idea that needs updating:)

  Looks a very cleva bloke to me:)...(EDIT: Not saying as cleverer as Doc but still awesome) EDIT 2: My attempt at humour was not in anyway aimed at maligning doc..If it comes across that way it is NOT meant to.

  Order of operations is a quaint dated idea that we really need to stop teaching and stop depending on.

   

  Lawrence Stewart, Research Computer Scientist

  Answered Jan 23, 2016 · Upvoted by Mark Harrison, BA (Oxon), MA (Oxon), Mathematics and Computation joint honours

• craigswan 31,821 Posts

  Tue, Aug 22 2017 6:40 AM