Are you familiar with sudoku or kenken puzzles? The number of combinations there is much higher. And yet grandmas on the bus are doing sudokus just fine. All that's needed for your problems is logic and a bit of arithmetic.
I do's - I got time I have not spent yet........
What on earth is that meant to imply?? What an ageist, sexist and politically incorrect comment to make. Think before you type!!
I'd love to see more of such questions in my son's school assignments. Not all 'real life' math problems come neatly wrapped in the "3/4+1/2 =" format.
Sorry for not including other family members and plane, train, and automobile riders.
That's not the point.
That is true but I'm sure that's not what was implied by the poster. The statement was implying the exact opposite.
My point was that people far removed from school math classes are doing logic/arithmetic puzzles. Why grandmas? I don't know, maybe because mine liked doing them. She was a teacher (not math). When I visited my grandparents over the summer she showed me how to do problems from next year's textbooks for fun. Limits and such. So I was not implying what you are implying.
Yep. The permutations of k items selected from n distinct items [MATH]= \dfrac{n!}{(n - k)!}.[/MATH]
Oh I agree that actual problems seldom come in pretty packages, but this one strkes me as so contrived and so arbitrary that I cannot imagine many children viewing it as anything but pointless. Puzzles are great (I love sudoku), but good puzzles have some sort of rhyme ot reason to them. Each of the nine positive digits must go once into each of the nine rows and once into each of the nine columns and once into each of the nine sub-squares. It appeals to the sense of order and fitness to the purpose. The set
Don't follow. Let's say I'm building a chair out of wood. I have some pieces I'd like to reuse. I know the dimensions of the chair and the pieces. How do I put them together? The dimensions of the pieces look like the integer set above - seemingly arbitrary set of numbers not related to anything. But they become "related" when we add the constraint of the chair they should eventually form.
Except in that practical example, you would have no way to know whether a solution exists, nor would you be constrained from grabbing a saw to shorten any piece that was too long or from changing the design of the chair to fit the wood available or from using some but not all of the pieces. The creativity would come, as an angineer once told me, from figuring out which constraints could be ignored.