James Fleming, post: 454313, member: 136 wrote: (2,3) + (3,4) x (10,11,15)
James thanks for posting a link to Emmy Noether.
JOHN NOLTON
Tom Adams, post: 454366, member: 7285 wrote: I follow the "rules of operation" because it is a "rule". However it is not real math logic. Like a legal description, you want to write it as best you can so as not to be mis-interpreted. I haven't found a case-law on the rules of operation as to whether the correct interpretation is by the order it's written down, vs. whether someone who didn't know the "rule" that the original author happened to be following. (As a surveyor, I think the best evidence would be when the author finally wrote down his conclusion. If I got a different answer, I could then research exactly what the author's intent or typo was. (ie, did he publish a bearing as NW instead of NE) If I were putting a formula into a document that is telling the reader what to use, I would probably use parentheses to clarify exactly what I wanted them to do (of course I guess you need to know the "rule" of doing what is in parentheses first, but it would still help point the reader in the right direction.)
However, it makes for a good trick-question, as does changing the number of bananas, polygons, and time on the clock. (Is a clock worth 3 points, or is the number of hours on the clock worth a point. If the clock was at the 12, would that be zero or 12?)
The problem can be viewed as being full of inferences, but perhaps the most important two are that an individual shape always represents the same number and that the value on the left side of an equation is always the same as the value on the right side. Then the first equation tells us that each of those shapes represents 15. In the second equation, the two bunches of bananas total 8 (23 -15), so each bunch is 4. Knowing that a bunch of bananas is 4, the sum of the two clocks is 6 (10 - 4). The final inference is relating the counts of clock numerals, bananas, and polygon sides to values.
My rheumy eyes didn't at first see that some banana bunches contained 4 bananas and others three. But the value proposition made me look closer and the answer appeared. I'm not sure if this problem tests "critical thinking" or "eyesight" or something else, but there's likely a genre that contains it.
As to order of operations as we know it, good ol' Dr. Math has some insight here: http://mathforum.org/library/drmath/view/72759.html
That proposition has been important for a long, long time, but it is supremely important in the digital age. The fact that inserting parentheses at many different places in, for example, an Excel formula, will satisfy Excel's edits does not mean that the formula produces correct answers. Thus, knowing where parentheses are needed and where they're not needed is extremely important and still a major source of error.
[USER=225]@JOHN NOLTON[/USER] Discover Magazine had a nice article about Emmy Noether back in June, I think, as did Smithonian. Both are available from a Google search.
MathTeacher, post: 454395, member: 7674 wrote: The problem can be viewed as being full of inferences, but perhaps the most important two are that an individual shape always represents the same number and that the value on the left side of an equation is always the same as the value on the right side. Then the first equation tells us that each of those shapes represents 15. In the second equation, the two bunches of bananas total 8 (23 -15), so each bunch is 4. Knowing that a bunch of bananas is 4, the sum of the two clocks is 6 (10 - 4). The final inference is relating the counts of clock numerals, bananas, and polygon sides to values.
My rheumy eyes didn't at first see that some banana bunches contained 4 bananas and others three. But the value proposition made me look closer and the answer appeared. I'm not sure if this problem tests "critical thinking" or "eyesight" or something else, but there's likely a genre that contains it.
As to order of operations as we know it, good ol' Dr. Math has some insight here: http://mathforum.org/library/drmath/view/72759.html
That proposition has been important for a long, long time, but it is supremely important in the digital age. The fact that inserting parentheses at many different places in, for example, an Excel formula, will satisfy Excel's edits does not mean that the formula produces correct answers. Thus, knowing where parentheses are needed and where they're not needed is extremely important and still a major source of error.
[USER=225]@JOHN NOLTON[/USER] Discover Magazine had a nice article about Emmy Noether back in June, I think, as did Smithonian. Both are available from a Google search.
Math Teacher, thanks for letting me know about Emmy in both Discover mag. and Smithonian-- I will look it up.
The simple problem seems to be as you state; critical thinking + eyesight + knowing ALGEBRAIC HIERARCHY.
JOHN NOLTON
I'm changing my answer to 38
Good Man RFC. (38)
JOHN NOLTON