Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: On Regents Exam
Replies: 11   Last Post: May 5, 2011 7:09 PM

 Messages: [ Previous | Next ]
 Roberta M. Eisenberg Posts: 40 Registered: 8/18/09
Re: On Regents Exam
Posted: May 4, 2011 3:07 PM
 att1.html (9.0 K)

Why don't you devise some problems with real world numbers in them, involving squaring or even cubing, sq rt, etc, and add one to every test or quiz? Make it so that the student who does not use enough digits will get the wrong answer.

I am particularly thinking of a Math A problem of about 10 years ago. It was a 3-pt. question about a circular garden with a circular path around it. The circles were concentric and the kids had to find the area of the path. All those who used 3.14 or 22/7 for ? rather than carry more digits or use the ? key on the calculator, lost a point. It seemed rather unfair at the time to lose 1/3 of the value of the problem (after correctly finding two areas and subtracting them) for a clerical error. Now I think that such an error is not only one of laziness but also an error in the concept of how many significant digits were required.

If an organization had hired a contractor/landscaper to make a
large outdoor flower bed, say with a 100' radius, they would be very unhappy if the price estimate was way off due to not having enough decimal places in the calculation of the costs. It is easy to see that four decimal places of ? are not enough in this case since the square of the radius would have four zeros, and you need one extra place in your answer for rounding.

What I would really like to see in this discussion is teaching the kiddies how to know in advance how many digits a given problem will need. Estimation and approximation are valuable skills.

Bobbi Eisenberg,
Chairperson UFT Math Teachers Committee

On May 4, 2011, at 11:07 AM, Daniel Knaisch wrote:

> Never had the pleasure of teaching Course 3, Started teaching during the reign of Math B. Although I know the importance of using all decimals displayed, when communicating that to students you can actually see my voice going through one ear and out the other (its an amazing sight). As I am lecturing on the importance, the reality still is these kids are thinking "if he thinks I am writing down all these numbers, this guy is nuts." Storing the number for a variable cures this problem, but again getting some of these kids to know the calculator keys is a tough job in itself. There is probably no way to get all kids to do what you ask them to anyway, and if you are getting every student to use the full display, then you should be deemed as teacher of the year. Regardless, Until I see a quesion where 4-decimals is not enough (in the Alg2/Trig), I have thrown in the towel on trying to get these kids to use the full display. I do mention it, and those of them that actually pick up on the importance can/will do it.
>
> would love to see the question where 4-decimals was not enough.
>
> Daniel Knaisch
> Math Teacher
> 933 Hoffman St.
> Elmira, NY 14905
> (607)735-3100 ext 4233
>
> From: owner-nyshsmath@mathforum.org [owner-nyshsmath@mathforum.org] On Behalf Of T Dempsey [dempseyt53@gmail.com]
> Sent: Wednesday, May 04, 2011 10:18 AM
> To: nyshsmath@mathforum.org
> Subject: Re: On Regents Exam
>
> Many years ago (Course 3!) I had students round to the 4th place and told them that should cover it. I was wrong. Many lost 1 point. Since then, we hold the full display of the calculator.
>
> On Wed, May 4, 2011 at 8:32 AM, Daniel Knaisch <dknaisch@elmiracityschools.com> wrote:
> From my experience, students are lazy and when they see the calculator spit out a decimal that is 8 or 9 places long, you start hearing the moaning and complaining that they have to use them all (even from the best students). This is a battle that you just won't win, so I have always told them to round to 4 decimal places no matter what. Going back to the "old days" when we used trig tables (some of you young bucks won't remember), but all of the decimals were rounded to 4 places. I have never come across a problem where rounding was skewed becasue of using only 4-decimals
>
> Daniel Knaisch
> Math Teacher
> 933 Hoffman St.
> Elmira, NY 14905
> (607)735-3100 ext 4233
> ________________________________________
> From: owner-nyshsmath@mathforum.org [owner-nyshsmath@mathforum.org] On Behalf Of mathpig [mirie@northvillecsd.k12.ny.us]
> Sent: Tuesday, May 03, 2011 6:45 PM
> To: nyshsmath@mathforum.org
> Subject: On Regents Exam
>
> There is a question using both the law of Sines and Cosines, and first you solve for a side and use it to find an angle. Say the side is an irrational number (ex. 10.254873209). Can a student round it to say the nearest hundredth and use it to solve an angle OR should a student use the 10.254873209 to solve the angle?
>
> I have always taught students to use the number and not to round it until the end (the answer) but just wondered if that is allowed.
> *******************************************************************
> * To unsubscribe from this mailing list, email the message
> * "unsubscribe nyshsmath" to majordomo@mathforum.org
> *
> * http://mathforum.org/kb/forum.jspa?forumID=671
> *******************************************************************
> *******************************************************************
> * To unsubscribe from this mailing list, email the message
> * "unsubscribe nyshsmath" to majordomo@mathforum.org
> *
> * http://mathforum.org/kb/forum.jspa?forumID=671
> *******************************************************************
>
>

Date Subject Author
5/3/11 mathpig
5/4/11 Thompson, Patricia
5/4/11 Daniel Knaisch
5/4/11 T Dempsey
5/4/11 Daniel Knaisch
5/4/11 T Dempsey
5/4/11 Roberta M. Eisenberg
5/4/11 Jennifer Sauer
5/5/11 Tom Kenyon
5/5/11 precopio@nycap.rr.com
5/4/11 ElizWaite@aol.com
5/5/11 Tennantij@aol.com