
Brian Bankler
United States San Antonio Texas
"Keep Summer Safe!"

Fill in the number in the following sequence:
423, 623, ???, 798, 846
I got this secondhand from a coworker. We both suspect that a number has been transcribed ... I don't see any obvious mathy progression (arithmetic, geometric), and those are beyond most 3rd graders anyway. It may be a lateral thinking problem where the numbers should be ordered by sound/alphabetical/shape.
Clarification  I put three question marks myself. There is no implication that the missing number has three digits, although I suspect it does.

J Boyes
United States Unspecified

The numbers seem to be increasing, but maybe not

Aloha!
United States Kalamazoo Michigan
Meega, nala kwishta!
AAGH! YOU'RE TOUCHING ME!

710.5. There's no logical progression I can see, but then, I'm hardly a mathamagician. I'm betting there have been some numbers swapped/changed.

Andrew Simpson
United Kingdom Leeds West Yorkshire

Bus numbers along the main road past the school?

¡dn ʇǝƃ ʇ,uɐɔ ı puɐ uǝllɐɟ ǝʌ,ı
Canada Chestermere Alberta
Life lesson: Hamsters are NOT diswasher safe.
There are 10 types of people those who understand binary, and those who don't.

Integrate, then divide by 2.
It worked for me on a calculus test, once.

Blorb Plorbst
United States Bloomington Indiana
I think we're all bozos on this bus.

This information is classified.

Andrew Simpson
United Kingdom Leeds West Yorkshire

Plug it into Excel, plot a graph and apply a polynomial trendline:
y = (6.0833 * (x^3)) + (80.083*(x^2)) + (397.67*x) + 99.333
x num y  1 423 423.0033 2 623 623.0074 3 735.8451 4 798 798.0162 5 846 846.0205
so the answer could be 736!

Josh Jennings
United States San Diego CA

LRayZor wrote: Plug it into Excel, plot a graph and apply a polynomial trendline:
y = (6.0833 * (x^3)) + (80.083*(x^2)) + (397.67*x) + 99.333
x num y  1 423 423.0033 2 623 623.0074 3 735.8451 4 798 798.0162 5 846 846.0205
so the answer could be 736!
Obviously this is right. Come on, guys. Even a 3rd grader could do this.

CHAPEL
United States Round Rock Texas
"that's a smith and wesson, and you've had your six"

Is the right answer underpants?

Stymie says, "No Fidgets"
United States SF Peninsula California
"Nobody down here 'cept us dummies"
"Betcha can't throw that donut on my finger"

The way math is now taught in the US makes me want to puke.
"Sit down children. Here is poorly written jumble of crap. I'm not going to teach you anything or help you. Get in groups and figure it out yourselves."
It's hard not to be a conspiracy theorist and think the gov't wants all of our kids growing up to be ignoramuses and thus easily controlled.

Steve Vondra
United States Charlottesville Virginia

42 ?

Mark Adams
United States La Mesa California

My son brought home something similar to this.
I'm pretty sure he just put down random numbers in order to say he was done with his homework

Blorb Plorbst
United States Bloomington Indiana
I think we're all bozos on this bus.

wysire wrote: The way math is now taught in the US makes me want to puke.
"Sit down children. Here is poorly written jumble of crap. I'm not going to teach you anything or help you. Get in groups and figure it out yourselves."
It's hard not to be a conspiracy theorist and think the gov't wants all of our kids growing up to be ignoramuses and thus easily controlled.
I think that's completely unfair and ill informed. First of all, the assertion that this an actual 3rd grade problem is third hand and the OP acknowledges that the problem may be incorrectly presented.
My 1st grader is performing math tasks significantly more complex than I was doing at his age. What he's being taught is not only instructive and practical but is integrated across the curriculum. I think it's providing him a sounder foundation in mathematical thought than I ever received when addition and subtraction were taught as just rote practice.
/screed

Stymie says, "No Fidgets"
United States SF Peninsula California
"Nobody down here 'cept us dummies"
"Betcha can't throw that donut on my finger"

CrankyPants wrote: wysire wrote: The way math is now taught in the US makes me want to puke.
"Sit down children. Here is poorly written jumble of crap. I'm not going to teach you anything or help you. Get in groups and figure it out yourselves."
It's hard not to be a conspiracy theorist and think the gov't wants all of our kids growing up to be ignoramuses and thus easily controlled. I think that's completely unfair and ill informed. First of all, the assertion that this an actual 3rd grade problem is third hand and the OP acknowledges that the problem may be incorrectly presented. My 1st grader is performing math tasks significantly more complex than I was doing at his age. What he's being taught is not only instructive and practical but is integrated across the curriculum. I think it's providing him a sounder foundation in mathematical thought than I ever received when addition and subtraction were taught as just rote practice. /screed
Well good for your school. I see a lot of bad curriculum in California.

Amy Wiles
United States Macon Georgia

wysire wrote: "Get in groups and figure it out yourselves." I can't speak to your particular situation, but there is a lot to be said for having students work something out or discuss it in groups before the teacher/professor lectures on it. It's actually the way I run a lot of my classes now.

Stymie says, "No Fidgets"
United States SF Peninsula California
"Nobody down here 'cept us dummies"
"Betcha can't throw that donut on my finger"

amwiles wrote: wysire wrote: "Get in groups and figure it out yourselves." I can't speak to your particular situation, but there is a lot to be said for having students work something out or discuss it in groups before the teacher/professor lectures on it. It's actually the way I run a lot of my classes now.
I agree if they are given a foundation to work from. A good teacher will do that. But I don't think it is happening as much as it should. So one kid in the group who understands how to do it, does it, and the rest are left behind and happy to let that kid do the work.
I am probably being hyperbolic. I'm not bashing all teachers. I just have concerns for those being 'left behind.'

Goo
United States Yorba Linda California
I have become my own island state. A ravaged, wartorn land where nothing grows and the horizons are bleak.

Bankler wrote: 423, 623, ???, 798, 846
No one? Nothing?
I want to know.
The last number is 2x the first number. That's gotta mean something.

CHAPEL
United States Round Rock Texas
"that's a smith and wesson, and you've had your six"

I have a feeling this is a "There is no wrong answer as long as you explain your assumptions" kind of questions.

Brian Bankler
United States San Antonio Texas
"Keep Summer Safe!"

CrankyPants wrote: wysire wrote: The way math is now taught in the US makes me want to puke.
"Sit down children. Here is poorly written jumble of crap. I'm not going to teach you anything or help you. Get in groups and figure it out yourselves." the OP acknowledges that the problem may be incorrectly presented.
Well. The coworker that gave me this has complained that some of his teacher friends (and his kid's teacher) do in fact assign homework before teaching the technique necessary to solve it. The rationale is that the kids will be more motivated to learn if they flounder ... and those who figure out it will be better off, too.
This strikes me as lunacy, although I've seen no evidence that my kid's teachers do this (I am not in the same school district as my coworker).
I have been reasonably impressed with what my kids are learning. However, I've been unimpressed by how they are being taught it. And, it's ludicrous to have elementary students studying (for example) Venn Diagrams or Converting Binary Numbers to Base10.
Of course, this varies immensely by state and district. (The "I" in NEISD stands for "Independent". It's not run by the city or state, although it complies with lots of regulation). So YMMV.

Blorb Plorbst
United States Bloomington Indiana
I think we're all bozos on this bus.

Bankler wrote: And, it's ludicrous to have elementary students studying (for example) Venn Diagrams or Converting Binary Numbers to Base10. I guess we'll have to disagree but both of those skills are very instructive. Venn Diagrams help visualize sets of things and their relationships, incredibly useful in all sorts of problem solving. It gives a tool for modeling information quickly and in a very precise format.
And understanding nonbase 10 number systems grants a much more thorough grasp of how our biologically selected base 10 number system functions  why we carry digits when we add, why multiplying by 10s is so simple (and why multiplying by 16 is simpler in hex than in dec AND why programmers think Halloween falls on Christmas). I never dealt with alternate bases until I was well out of college and quite frankly it made a huge lightbulb go on in my head.

Amy Wiles
United States Macon Georgia

Bankler wrote: And, it's ludicrous to have elementary students studying (for example) Venn Diagrams or Converting Binary Numbers to Base10. I don't understand why this is ludicrous. Venn Diagrams are a great mechanism for understanding how items relate to one another. I've already introduced them to my fouryearold. I can also see how binary conversion might help learning about the number system. Maybe it's not what you would teach, but I can't see how it's ludicrous. And I can imagine that your kids would do just fine with these concepts.
Homework for anything below about 4th grade, however, is lunacy, IMO. Maybe a book report every now and again, but that's about it.

Pieter
Netherlands Maastricht
Good intentions are no substitute for a good education.
I take my fun very seriously.

Bankler wrote: Well. The coworker that gave me this has complained that some of his teacher friends (and his kid's teacher) do in fact assign homework before teaching the technique necessary to solve it. The rationale is that the kids will be more motivated to learn if they flounder ... and those who figure out it will be better off, too. I have seen my daughter get homework like that. She asks me how to solve a problem and I tell her what technique you have to use. She then tells me that that is something they haven't learned yet. I look in her books, and indeed, what you need to solve it is in the NEXT lesson. Not laziness or something on her part, she is quite good at math.

howl hollow howl
United States Oregon

I read in a recent Games magazine about the hardest riddle in the world that more kids get right than adults. You could show that progression and ask "Do you know what number should go there"?
Spoiler (click to reveal) Answer: No
Bankler wrote: The coworker that gave me this has complained that some of his teacher friends (and his kid's teacher) do in fact assign homework before teaching the technique necessary to solve it. The rationale is that the kids will be more motivated to learn if they flounder ... and those who figure out it will be better off, too. I heard an interesting NPR piece recently about researchers who found that Eastern kids will tend to spend up to an hour on such problems, even problems that are impossible, whereas Western kids tend to give up right away. I like to think that my daughter  adopted from China  is evidence that it's environment and not genetics.
Bankler wrote: it's ludicrous to have elementary students studying (for example) Venn Diagrams
You high. Venn Diagrams are great for basic logical thinking, and are useful tools for compare/contrast assignments. In our homeschooling, we use Venn Perplexors by Mindware for basic logic & math thinking, and then use Venn diagrams in other disciplines (most recently, to compare Newton & Locke).

howl hollow howl
United States Oregon

Ha, concurrent dogpile!

Mike Norris
United States Sacramento California
...and JPop too!!!!
Raina rocks!!!!!

Ah...i got it! The answer is: "XXX"
Because XXX makes any math lesson better.



