How long does it take your 7th grader to do this division problem?

[PaigeP]

(If this becomes a double post.....excuse me...I just thought I submitted it and I couldn't find it, so I'll post again....).

 

Last evening my next door neighbor came over and saw that we had a new large dry erase board. She's in 7th grade at the local public school (which is among the top in our state -- in fact, her particular school is the TOP in math in our state among other 6A schools). She's in pre-algebra and is making "straight As." From what I've gathered over the years, she's a great pupil and has always made straight A's. I wrote a math problem on the dry erase board for her to work on. The math problem was: 646 divided by 42. I timed her (she didn't know I was timing her so she was anxious about working on it).

 

She worked on it for about 4 minutes and, even after that, her answer was wrong. (and I purposefully wrote what I thought would be an easy one for her to be able to easily do in front of my child).

 

After she finished, she said, "It's been a while since we did long division; we're on square roots now."

 

Just curious how long it takes other 7th graders to do this problem.

 

My oldest is only a 2nd grader so we're not there yet to be able to compare.

 

 

Thanks,

Paige

[boscopup]

My 3rd grader just did it in a minute and a half. He just finished the long division section of SM5A, and he hasn't been doing double digits divisors very long.

 

I would be concerned if my child forgot how to do long division while doing other topics.

[armom]

So, out of curosity I had my 6th grade student do this question just now. It took her 2 minutes and got it correct. I don't think 4 minutes is unreasonable, as my son would have taken longer to do the problem than my daughter. (they are twins).

[Cosmos]

To how many decimal places? ;)

 

It took my 7th grader about 45 seconds per digit. When he got to three decimal places, I told him to stop. That was about four minutes.

[Cosmos]

My 3rd grader just did it in a minute and a half.

 

My 10 year old could do it in a minute in his head.

 

So, out of curosity I had my 6th grade student do this question just now. It took her 2 minutes and got it correct.

 

Wow, I'm impressed!

 

How far did you all carry the division?

[boscopup]

Wow, I'm impressed!

 

How far did you all carry the division?

 

We did a remainder. I would have to time him again carrying it to decimal places (he's done that before, but not had much practice with it).

[txmommyofboys]

It took me (31 years old) about 11 seconds on the calculator lol jk

[KAR120C]

When DS was little and flying through math at an alarming rate, it occured to me that I should work ahead and make sure I was up to speed on everything before he got there. I wasn't actually worried - I've worked as a statistical analyst and database programmer, I had A's in three semesters of calculus, I'm a math tutor for Pete's sake! But actually, I hadn't done long division by hand in forever... and when I sat down to work that *&^%$# fifth grade Singapore exercise, I honestly couldn't have remembered how to do it to save my life.

 

I'm not saying it's not a sorry state of affairs; just that I wouldn't judge a kid by long division. I might have some pointed opinions about the curriculum... If kids are taught procedure by rote (as I know I was a billion years ago in elementary school), it is hard to keep those steps in mind if you're not practicing. It may be hard even if you understand the reasoning, but you should be able to hack your way through. At this point, having all the background I already had plus several years of math competition coaching (much more problem solving than I ever had to do before and much more creative hacking-your-way-through), I doubt I'd ever forget long division again. But ask me in twenty years when I've (with any luck) gone back to statistics and databases, and long division is a relic from a former life. ;)

[armom]

My daugther got the answer with a fraction. We are just starting decimals this week.

[PaigeP]

Thanks all.

 

To answer the question about how far I had her carry the remainders:

I had her stop after the hundredth place so her (incorrect) answer was like 14.65.

[EKS]

I did it myself. It took me 3 minutes, but I carried the division out until I found where it started repeating (7 places). And, FWIW, I wasn't hurrying.

Edited September 26, 2012 by EKS

[dmmm]

I agree with KAR120C.

[boscopup]

When DS was little and flying through math at an alarming rate, it occured to me that I should work ahead and make sure I was up to speed on everything before he got there. I wasn't actually worried - I've worked as a statistical analyst and database programmer, I had A's in three semesters of calculus, I'm a math tutor for Pete's sake! But actually, I hadn't done long division by hand in forever... and when I sat down to work that *&^%$# fifth grade Singapore exercise, I honestly couldn't have remembered how to do it to save my life.

 

I had this experience when doing long division with a decimal divisor. I tried it one way that did NOT work well, and I had to look it up in MM5 to see how to do it. Once I looked it up, I was like, "Duh! I knew that!" :lol:

 

But I haven't done long division with a decimal divisor in almost 20 years. I do think there is a difference between that and a child that is currently doing prealgebra and is doing such math every day. That child has at least done it in the last year. I can remember it now, since it I looked it up several months ago. :D

[Tasia]

My 6th grader did it to three decimal places in about 20 seconds. His pencil never stopped moving, so I don't think that's normal. My 8th grader did it to two decimal places in a little over two minutes. That seems about right. But, they've both reviewed division within the last two months.

[caayenne]

My 10 year old son just solved it in just under a minute. If it had been on his math assignment for the day, he might have taken a bit longer, but he is very motivated by competition when it comes to academics. :D

[Crimson Wife]

I did it myself. It took me 3 minutes, but I carried the division out until I found where it started repeating (7 places). And, FWIW, I wasn't hurrying.

 

It took DD just under 3 minutes to divide it out to where it started repeating.

[Monica_in_Switzerland]

If I had to guess, she is probably a perfectly fine student... but is allowed to use a calculator. Which means, once they covered the concept, she probably never practiced again. It's really too bad that so many teachers allow calculators before Calculus.

[AimeeM]

For what it's worth, my daughter can solve multi step equations, is wonderful with decimals, order of operations, exponents, etc, but division with two digit divisors make her want to cry :D.

[didadeewiththree]

It took my 7th grader one minute to do this problem. :grouphug: :smash::smash::smash::iagree:

[hunt]

It took my 7th grader to do that problem in about one minute.

[Violet Crown]

My 4th grader got 15 8/21 in 63 seconds. Not counting the time it took her to pause and ask if she was "allowed" to write out the computations underneath or if she had to do those in her head. :confused:

 

Death to calculators.

[thebacabunch]

I always hear homeschoolers complain about the community at large giving their kids pop quizzes to prove how ineffectual homeschooling is. Is this the same kind of thing?

[dmmm]

:iagree: