Second Grade Math Riddles--How would you answer?

[Zeldar]

@belladonna

So my second grader brought home these 2 riddle-type questions on a math worksheet and I’m soliciting opinions on how others would answer, and why.

This was a week ago, they’ve already been answered, turned in, and graded so no one will be helping a seven year old cheat here. However, the answers I insisted he use–which he vehemently protested–ended up being marked wrong. Aghast So now I’m in hot water with the kidlet. I’m not saying what we answered, to prevent muddying the waters, but I’m dying for a little validation here.

1. Mrs. Carter saw some animals in her garden.
   All of them were chickens except one.
   All of them were roosters except one.
   Can you figure out how many animals are in her garden?
2. Mr. Carter had some animals in his pasture.
   All are cows except two.
   All are horses except two.
   All are sheep except two.
   Can you figure out how many animals are in the pasture?

I haven’t read any further than the OP.

1 – Answer: 1 rooster and one non-chicken
2 – Answer: 1 cow, 1 horse, 1 sheep

Now I’ll see how I would fare in second grade.

[CCYMan]

@kittenblue

And I had no idea at all about using Ctrl-A to reveal spoilers! Thank you so much!

Me either!

I read that part about “you all are just going to use Ctrl-A anyway” and was immediately intrigued. I tried it, and it was like the clouds parted and a ray of light shined down. Then I thought “you mean all this time I’ve been manually dragging over the spoiler boxes to get to the goodies?”

Ignorance fought.

[Gus_Gusterson]

@belladonna

He had it right! He said “NO”. Can you feel my pain?

I’m curious as to why you overrode him. It was his homework. I have no problem with helping my kids with their homework, but if they get the answer wrong I let them get it wrong. I might ask, “Are you sure?” (I sometimes do that when they have the answer right, too, to see if they really understand what they’re doing), but I don’t correct them.

[Ice_Cream_Man]

Maybe the answer is NO because it states that she saw some animals but not that she saw ALL the animals. Maybe there were animals in the garden/pasture that she didn’t see.
Mice? Insects? Birds? Snakes?

[SciFiSam]

@CCYMan

Me either!

I read that part about “you all are just going to use Ctrl-A anyway” and was immediately intrigued. I tried it, and it was like the clouds parted and a ray of light shined down. Then I thought “you mean all this time I’ve been manually dragging over the spoiler boxes to get to the goodies?”

Ignorance fought.

Glad to have helped on that one! I loves ctrl key.

@Ice_Cream_Man

Maybe the answer is NO because it states that she saw some animals but not that she saw ALL the animals. Maybe there were animals in the garden/pasture that she didn’t see.
Mice? Insects? Birds? Snakes?

Ooh, now THAT makes sense to me.

[Indistinguishable]

@ZenBeam

Yes, because that implies to me there are at least two students in the hall. But no one is arguing that zero animals is a possibility for either question.

I had the same initial reaction, but actually, read the bit you quoted more carefully. It is exactly analogous to the animals situation; “all of the students are in the hall except for two [who are not in the hall].” This doesn’t imply there are two students in the hall; it states that there are two students not in the hall.

[belladonna]

@Gus_Gusterson

I’m curious as to why you overrode him. It was his homework. I have no problem with helping my kids with their homework, but if they get the answer wrong I let them get it wrong. I might ask, “Are you sure?” (I sometimes do that when they have the answer right, too, to see if they really understand what they’re doing), but I don’t correct them.

I always let him do his homework on his own, then check it afterwards. If he gets something wrong, I work with him to correct it. He’s a bright kid, and usually sees his mistake immediately. As to why—I suppose it’s because I see it as my job to make sure the work he completes under my watch is correct, guess I failed on that one here, eh?

Originally Posted by Ice Cream Man
Maybe the answer is NO because it states that she saw some animals but not that she saw ALL the animals. Maybe there were animals in the garden/pasture that she didn’t see.

This makes sense to me too. Not that the other responses weren’t technically correct, but they all seemed a little too high-concept for a second-grade level worksheet. And this also fits with the teacher’s response that “some” was the key to the question. Nice.

[ZenBeam]

@Indistinguishable

I had the same initial reaction, but actually, read the bit you quoted more carefully. It is exactly analogous to the animals situation; “all of the students are in the hall except for two [who are not in the hall].” This doesn’t imply there are two students in the hall; it states that there are two students not in the hall.

Oh, you’re right. I read it as “all the students in the hall, except two”.

But again, in what scifisam2009 really wrote, “all the students are in the hall, except two”, “all” does refer to all of the students. “all except two” refers to the student in the hall.

[gigi]

1. Mrs. Carter saw some animals in her garden.
   All of them were chickens except one.
   All of them were roosters except one.
   Can you figure out how many animals are in her garden?

Two animals - one chicken, one rooster.

2. Mr. Carter had some animals in his pasture.
   All are cows except two.
   All are horses except two.
   All are sheep except two.
   Can you figure out how many animals are in the pasture?

Three animals - one cow, one horse, one sheep.
::grits teeth and hits Submit Reply

[Indistinguishable]

@ZenBeam

But again, in what scifisam2009 really wrote, “all the students are in the hall, except two”, “all” does refer to all of the students. “all except two” refers to the student in the hall.

Yes, and this is true of the animals situation as well; I may have confused things before, but you put it very well: in neither of the problems in the OP does “all” itself refer directly to 0 many things; rather, they both use the construct “all except n many” where the “all” refers to n many things, so that nothing is left over once all the exceptions are accounted for.

[gigi]

OK, I’m going to defend one chicken, one rooster byt saying that in second-grade-land, this is a chicken

http://www.mce.k12tn.net/reading48/hen.gif

and this is a rooster:

http://sands-publishing.com/maureenbarry/image/Chicken%20Rooster%20blank%20gif.gif

So a rooster is not a chicken.

“Something’s missing all right.”

[Gangster_Octopus]

1. Mrs. Carter saw some animals in her garden.
   All of them were chickens except one.
   All of them were roosters except one.
   Can you figure out how many animals are in her garden?

No, there may be one animal that is neither a chicken or a rooster. Or there may be two, 1 rooster and 1 chicken or 1 rooster or chicken and one other animal.

2. Mr. Carter had some animals in his pasture.
   All are cows except two.
   All are horses except two.
   All are sheep except two.
   Can you figure out how many animals are in the pasture?

No, there could be two animals that are neither cows, horses or sheep. There could three, one of each of the former, or one of the former and two of any other combination of animals, but not two of the former animals (i.e. there could not be one cow and two horses). Or there could be four, 2 of one of the animals and 2 of another.
Something like that.