From: Tim Kurtz (a.k.a. Prof. Maths - the original 'Dr. Math')
Subject: Professor Maths
You have done a nice job with the Math Forum and with Ask Dr. Math.
My project has not been officially running for several years since I left the
mathematics department at St. Bonaventure University. My address lives
on though, and I get several questions each week.
I recently received a request for the name of the horizontal line in a
fraction. Upon searching your archives, I came across an entry on the
same subject in which you shared the words virgule and solidus for the
diagonal line. It is used in the following ways:
to mean "per" miles/hour
and to delineate line breaks Old King Cole/Was a merry old soul.
I shared this with the fifth grade student from Australia but I would like to
address his real question. What is the horizontal line called? Got any
ideas, or who to ask, or how to proceed? - Prof. Maths
[See the Dr. Math FAQ - Math Terms: "What do you call the 'fraction bar'?"]
From: Travis Johnson
Subject: Thank you!!
Thank you very much for your time and quick response! This is a great
service for those of us who are "mathematically challenged"! I only wish
I could repay the service.. - Kim Johnson
From: Anthony D. McKenzie
Subject: Thank you
Thank you so very much for responding to my question. You really helped
me out a lot. My math teacher said that there was only one way to solve the
problem in every situation. Your answer proved my math teacher wrong
for once. Thanks again!
From: Tammy Goble
Subject: Re: Complex Number Applications
I greatly appreciate the time dedicated and information given in your
response to my question about complex numbers. I never dreamed I would
get such a thorough response. I was very impressed with your attention to
detail. Thanks so much for the information!
Subject: Re: Pre-algebra
Thank you sooo very much! We checked the problems in pre-algebra and
the answer that you sent me was correct. It was so simple that I was
reading somthing that wasn't there. I really appreciate you taking the time
to write me back. Off the subject do you have any kids that are my age that
would like to correspond? I'm 14. Thanx ;)
From: Meenakshi Chauhan
Subject: A special thanks
Dear Doctor Allen,
I am very very thankful to you. You replied back to my message the next
day. I had never expected a reply so soon from you. I did my test very
nicely, and hope to get good marks.
Thank you very much, - Meenakshi Chauhan
From: Meghan R. Busse
Subject: Thanks, Dr. Math!
Dear Ken "Dr." Math -
In April last year you answered a question about how to use latitude and
longitude to calculate distances. This was exactly the question I needed an
answer to today. I have included a little Excel spreadsheet that implements
exactly your calculations, for your or anyone else's interest.
I found the Dr. Math site by searching Yahoo!, and browsed around a bit.
I have to say, it is a terrific idea, _extremely_ cool. Keep it up, and thanks
again. - Meghan Busse
From: Todd Edwards
Subject: Re: Square with same perimeter and area as a triangle
Thank you so much for your thorough proof regarding my square/triangle
problem. I can't tell you enough how happy I was to hear from you. I was
really excited by this problem, but quite frankly haven't had a lot of time
to try and solve it. It's exciting to know that a resource such as yours
exists. I told all of my students about Dr. Math and have encouraged them
to visit your Web site.
I've used a good number of lessons from your site and have found them
really great! Keep up the great work. You help me feel "connected" to a
larger mathematics community - which is important for high school
teachers! Thanks again,
Upper Arlington High School - Columbus, Ohio
From: Robert P. Herbst
Subject: distances between points on a sphere
A big T H A N K S for your help making this information available.
Your text with the solution was adaptable to my problem. I used the
formula for determining distances between an entered home zipcode of
a customer who was searching for available dealers within a specified
driving distance of his/her home. A complete table of all zip codes comes
with a lookup table listing the latitude and longitude of all the zipcodes.
Interesting was my need to adapt the formula to radian measure as
required by the hardware.A nice exercise.
You're a good man to know. Will keep your address filed for future
reference. Thanks again. - Bob Herbst
From: Andrew Sherk
Subject: Rd: vector proofs and linear combinations
Thank you Doctor Anthony for your most prompt response! I give Doctor
Math many thumbs up! - Andrew
From: John S. Egan
Subject: Re: Volume of water
To Dr. Tom, The Math Forum
I just wish to thank you for giving me the formula for figuring the volume
of a sphere the size of our earth. I was unable to do the problem until
tonight because I had to find out from my son how you work with such
large numbers with the computer. It is really nice of you to offer this
service and I surely do appreciate it. Thank you.
Very truly yours, John S. Egan
From: Cheron Frazier
Subject: Many thanks to you
Dear Dr. Kate:
Thank you so much for responding to our math problem so quickly. I
actually sent the question in on behalf of my son, Julian (16 yrs), as he has
this problem in his physics class and hadn't a clue as to how to solve it.
When I first set us up on the web I bookmarked a whole library of
reference sites, categorically arranged, i.e., math, science, etc., believing
my teenagers would actually use the library if they didn't have to dig too
deep for a starting point. Dr. Math was number one in the math folder, but
they just weren't interested in checking it out. So, when my son came to me
with this problem I took it as an opportunity to hop on line and e-mail your
site with the problem while he was standing next to me.
I just wanted to let you know how impressed my son is with the internet
now because of you. I too am impressed by your clarity, in that I actually
(almost) understand the concept of the problem now that you've explained
Again, Thank you. - Cheron Frazier, San Marcos, California
(P.S. Thanks to you, I think now my son views the net as more valuable
than just someplace to try to "sneak" to XXX sites.)
From: Amanda Piedra
I would like to take a minute to tell you that Dr. Math is the best thing on
the Web. It helps me every time I have a question about something and
don't want to ask my dad. You are the smartest bunch of people I've ever
seen. Sincerely, Amanda
From: Richard White
The cylinder in the sphere problem made its way into Ask Marilyn
but her answer was really difficult to interpret. Your explanation is far
clearer... Thanks. - rw
From: Kimberly Kirkpatrick
Subject: Kudos, Dr. Math!
I just wanted to congratulate you on a wonderful idea. Dr. Math is
wonderful and I have a feeling we will see similar programs around the
country in the near future. Good job!
From: Mr Basudeb Gupta
Subject: Re: trigonometry
Dear Dr. Math,
I want to thank you for helping me in the tough mathematics problem.
Following the method you had stated in your e-mail it took me very little
time to arrive at the result. I appreciate your help and I will look forward
to your guidance if I am in trouble again. Regards, Chitrak Gupta,
From: Nathan Chute
Subject: Re: Thanks centroid of a triangle
Thanks so much for such a speedy reply (4 hours). This is an example of
the real reason there is the Internet.
From: G Schueler, Uni-Regensburg
Lieber Dr. Math,
Wir vom Goethe-Gymnasium in Regensburg schicken Ihnen GruBe!
From: Vern Klein
Subject: The hole in the sphere math. oddity.
To: Dr. Rob, The Forum.
Thank you for the prompt and very good response to our question about
the hole in the sphere and the constancy of remaining volume of the
sphere! Now we understand the "problem" and see how the unspecified size
of the sphere is actually dictated by the diameter of the hole one chooses to
bore through it. Your ASCII Art was really quite good. It was certainly
very adequate for me to make sketches to show my friend, Merilee. ...
we're going to get involved in quantum mechanics concepts and neither
Merilee nor I can clain much expertise in mathematics - we may be back to
Dr. Math!... Again, thank you for resolving the hole-in-the-sphere problem
for us! We won't spin our wheels on that one any more. May the new year
be good to all of you there! - Vern and Merilee
From: Timothy Basaldua
Organization: University of Illinois Chicago
Subject: Great Place To Visit
I'm 52 years old and find myself back in college struggling with
mathematics. Thank god I have stumbled onto this site. Just reading the
questions and your answers has already been a great help to me. Thank
From: John H
Dear Dr. Sarah:
Thank you for your help on mean, median, mode. I think I can finish my
homework before class today. I'm so glad I've found Dr. Math! Now I
have a Math Buddy at my fingertips at home - very reassuring. - John H
From: Linda Hood
Subject: dividing fractions
Thank you so much Dr. Math! I am a college student at Illinois State
University in Normal Illinois. I am majoring in Elem. Ed and I ran into a
problem that you helped me with. In my math methods class I have to
explain why invert and multiply works when dividing fractions. I had no
idea until I checked your website and there was an explanation. I'm so glad
that you take the time to help people with their math questions (even
college students!) Keep up the great work. - Linda Hood
From: Mervyn Hahn
Subject: Re: Writing Linear Equations in Point-Slope and Standard Forms
Dr. Keith -
I would just like to thank you very much for the 4 pages that you wrote me
on slopes. It really helped me out, and I appreciate all of the time you took
to write it. Thanks! - Lauren
From: E. Chapman
Dear Dr. Math,
You have never answered my questions directly, but you have helped my
partner SO much with our geometry project! Thank you SO much! I was
getting confused just trying to explain it to her!
Subject: Re: division, rule for dividing by 7
Thank you so much for helping me with dividing a number by 7. Two of
my other friends also needed to get this answer so they say thanks! I'll
recommend you to all my friends!
From: Sebastian Leske
I recently discovered the 'Math Forum' pages and I've been especially
amazed at the loads of interesting questions and answers. I'm currently
studying mathematics at a university here in Germany, but I never quite
realized how many interesting problems there are even on the elementary
school level. I can only congratulate you on your choice of problems and
on the imaginative and well written solutions you provide!
From: Heather Foster
Hi - thanks for the help! I came to look for a common multiple and
found out thanks to you, Dr. Math!
Sincerely, Heather Foster
From: Vasha N. Rosenblum
Subject: Re: request permission to share
Thanks for the permission to share the Dr. Math site. The first presentation
was a bit scary because I was using a zip drive (new hardware for me) and
new software (WebWhacker), but it went off without a hitch. People were
very enthusiastic about the information! Next presentation in Atlanta, Feb. 27...
I like showing kids the site and looking at the kinds of questions people
send in and what answers are given. It gives me ideas for problems to give
my students, with some background info provided by "Dr. Math" that helps
me ask appropriate questions to probe thinking. In other words, it teaches
me some mathematics that supports my teaching. (Elementary teachers
don't generally enter the classroom well prepared to teach math, and we
need all the help we can get!)
When I look at the archives with small groups of 2nd, 3rd, 4th, or 5th
graders, they never want to stop! They clamor for me to click on one more
topic to see what is there. The site serves to broaden their horizons from
school math to seeing math as a rich, varied topic. ...It is very interesting
to see what kids ask. There is a lot to be learned right there, since we
assume they think in certain ways and their questions reveal quite a
different story. Who would expect primary students to wonder who made
up zero, or who invented the plus sign!
I am so grateful for anyone out there helping teachers do a better job of
teaching, that I'm not much good at thinking up ways to do it better!
Swarthmore has done a super job of providing support for math at all
levels. We also have just started looking at the POW. What a great idea to
have visiting math mentors to share the work load of looking at the
responses and posting solutions. Thank you!
Vasha N. Rosenblum, Presidential Awardee Elementary Math '93
South Shades Crest School, Hoover, AL
From: Michael Barnes
Subject: Love you guys
I just want to thank you because I don't need help that much but when I do,
no one can help me but you guys. Thank You a Bunch and I might need
From: Jane Hicks
Organization: Glenlyon-Norfolk School
Subject: Thanks for the help!
Many thanks for your help tonight with my sixth grade daughter's
homework question- "what is an eleven sided polygon called?" Your site
was found through the Internet Public Library site, and was also referred
to in a recent article in the Vancouver Sun.
She had been sent home with instructions not to ask her mother, me, a high
school math teacher, and frankly, the magic of searching your site was just
as good as finding the answer. After all, we all know that finding an
elegant solution is the true beauty of mathematics! She tells me that the Ask
Dr. Math site was as close to asking me as she could get. Many thanks for
your help. By the way, my husband was very impressed that we were
talking to The Math God, John Conway.
Jane Hicks, B. Math '74, University of Waterloo
From: Harold Deskins
I really do not have a question. would just like to tell you guys what a
great site you have here. I see many questions (both on your pages and in
life) as to why math is important. I myself once thought that "I will never
use this stuff." Now I wish I had paid closer attention in class during high
school. As an Economics senior at Radford University, I find a greater use
for math with every passing day. Whether it is integrals, statistics, or
whatever, math plays a very important role in my studies.
I just wanted to let you guys know that yours is the first page I have found
that is so complete. I use this page often. It is interesting to go back and
brush up on some of the things that I have forgotten as well as learn new
things and applications from the questions of others. Again, I salute your
efforts and it is very much appreciated. It is my opinion that yours is the
best math related page on the net. Thanks, Harold Deskins
From: Debra Hope
Subject: Re: geometry -Reply
I am so excited! Thank you so much! It was my first time tracking you
down. I had heard about you from other kids at school. I am in the 5th
grade at PK Yonge Developmental Research School at the University of
Florida. After sitting at the table fussing with Dad about who was right,
(my dad thinks there are six edges on a cube and I think there are twelve
edges - who is right?) we headed to the Internet! I was very excited to see a
reply so quickly and the explanation is awesome. If that doesn't convince
Dad I was right, nothing will!
Thank you so much for being out there to help us kids. It is very exciting
that so much is available to our generation through the Internet. Thank
goodness for the computer nerds! Have a great day...hope to talk to you
again! - Tyler Hope and my Mom who agreed with me.
From: Michelle Dombeck
Subject: No question, just a big THANKS!
Dear Dr. Math,
I just want to take a moment to thank all you great people out there who
dedicate your time to help out frustrated kids like me. Your great site has
helped me more than once, and almost our whole math class uses your site
to help us, too. I like the variety of questions you keep in your archives
that save time for everyone. I hope you people continue to do this for a
long time. THANK YOU! - Michelle
From: John Lesniak
Yesterday I submitted a question on limits and factoring a polynomial that
had been bothering me for several days. Your incredibly prompt response
was highly appreciated. I haven't studied math in 25 years and thought I'd
see just how much I've lost. So I went to the local library and checked out a
textbook. There are a lot of gaps I have to fill. Your response was a clear
as any I've ever received from a teacher, and I've had some good ones.
Unfortunately, by the time I got into the heavy stuff at Cornell, they
figured you were smart enough to digest it from a non-native English
speaker. Not me. So I drifted into the "soft" social sciences and the rest is
history. Thanks again!
From: student e8926506, Technische Universität Wien
Subject: Ask Dr. Math
Dear 'Dr. Math', Vienna, 97/05/06
We are students of Vienna's Universities running a private information
page called Austria Information Switchboard. Every week we select one
page from the mass of internet offerings for its information value.
This means for our visitors they will find interesting and well presented
information which are worth the time to spend a visit. Your pages on Math
are the Information Value we have selected and introduced this week on
Mai 03, 1997.
You can visit the page at http://stud1.tuwien.ac.at/~e8926506/infoval.htm
Congratulation for your good work. - Ed
Subject: Re: Math Logic Puzzle
Hi Doctor Daniel,
Thank you so much! I tutor Algebra students so I will be telling them all
about your site! What a great place for our kids to come even when their
mom who loves math gets stumped! Thanks again. - Debbie Campbell
Subject: Re: Converting cubic yards to sq. ft.
Thanks very much for responding and broadening my basic math skills. It's
great to see people still take the time to help other people. Again, thanks.
From: Denise Clevenger
Subject: Thank you
On April 29th, you e-mailed my son Justin back with the help he requested.
As his parent, I just wanted to say God bless you! My son was able to finish
his homework without it turning into a stressful situation for both of us. It
is interesting to know that my son was the only student in that 7th grade
math class who turned in his homework the next day. I am sharing our
discovery (you) with my son's math teacher and his classmates. Thank you
again, you're an angel.
Dear Dr(s) Math,
I am an engineer with a bunch of kids, and I typically teach a class for each
of them once or twice a year. I was asked this time to teach multiplying and
dividing fractions. I stumbled across your web site, and will be using some
of your solved problems in my lesson. I'm used to dissecting frogs and
building small bridges, and was concerned that this would be a mighty dry
lecture. Your material will be a very big help. Thanks for your help, and
for your commitment to educating kids. - Paul Stone
Let me preface my question with a sincere thanks to everyone who has
helped me solve previous problems which I have submitted. I am actually
beginning to grasp some of the concepts which I have inquired about, and I
must dedicate that achievement to the help of your staff. Anyway, to get on
with my question...
From: Scott Olendorf
Subject: Re: Volume of cylinder, partially full, on its side
Wow, that works great. I just entered that into my spreadsheet and
produced a table with every 1/4 inch measurement and how many gals.
That's probably the first time I every really had a need for geometry after
college. - Scott Olendorf
From: M. DePinto
Subject: Re: Geometry
Thanks so much for the help. As a parent of three, this is a great resource.
I'm surprised at how much I managed to forget - it can be difficult to help
with homework once they advance beyond the basics! - M. DePinto
Subject: Volume formulas
I really appreciate your help! As a home school teacher, I visit this site
often. It has been a big help - sometimes I just get stuck! Thanks!
From: Monte Richardson
Subject: Re: percentage of savings
Dear Dr. Math:
Thank you for the quick response to my question. Besides just answering a
question you have reminded me of some math processes that I have
forgotten over the years. The educational function has again been fulfilled.
I will certainly keep you in mind for the next time that I get stumped.
Thanks again - Monte Richardson
From: Alexander Chupachenko
Hello Doctor Mitteldorf,
Thank you very much for the description of
x1 = x*cos(t) - y*sin(t)
y1 = y*cos(t) + x*sin(t)
formulas. Your information was really very useful for me and now I have
no problems with those formulas. Thanks, Alexander.
I think that what you are doing here is a great idea. I think that it will
encourage people to do their homework even if they don't really know
how to do it. Now, they have some one to ask besides their math teacher
or a family member. Plus it is a great way to get the knowledge of the
internet. I believe that it is, by the old saying, killing two birds with one
stone. They are getting the answer(s) to their question(s) and exploring
the internet. I would highly recommend this site to students and teachers.
I commend you with a job well done! Keep on answering your questions.
From: Becky Smith
Subject: Tesseracts and hypercubes
Thanks so much for helping my student with some information sources for
tesseracts on the Net. I'll keep this communication on file for future
reference on this topic. Your site is a great place for, not only students,
but teachers and media personnel to get mathematical information.
Becky Smith, Media Coordinator, Hickory High School
From: Brown Family
Subject: Re: Fibonacci Sequences\Numbers and Golden Ratio
Thank you so much, you've helped me the most out of everyone that's replied
to me on the Net... I greatly appreciate it. Now I can finish my assignment.
Thank you once again, - Kevin.
From: Richard Stack
Subject: Your Internet page
My class just started to study fractions and I came across your
Internet page. I think your page is really interesting and I thank
you for setting it up.
From: Mark Robbins
Subject: Linear equations
I just wanted to thank you for a very excellent service. My
sixteen year old son was having problems solving and graphing
linear equations. Being an electronics technician myself, I have
no problem solving them; unfortunately, there were specific ways
in which he was required to solve them and techniques he had to
understand such as standard form, y-intercept, etc. After my
first session resulted in teaching him using a method he would
not learn in class for two weeks, I knew I needed some help.
Your service gave me the quick re-cap and enabled me to explain
to my son in terms he was familar with.
I got to the page that I used using Webcrawler:
Thanks again, - Mark Robbins
Subject: A surveying problem
Thanks for your incredibly fast response to my question. I am
going to have to sit down and work at this a bit but I think I can
get it from here thanks to your help. I really appreciate this.
From: Lettie Witt
Subject: Factoring polynomials. (algebra)
Dear Dr. Math,
I am writing on behalf of and at the request of my granddaughter
who wrote you on Sunday regarding 8 (!) problems that had her
stumped. She currently has online access only through my account,
so she asked that I let you know how much she appreciates your
prompt and helpful reply to her algebra questions. She is doing
some advance work this summer and had calculated she needed to
complete 7 pages each day to finish before school starts in the fall,
and these problems had her stymied. Upon receiving your helpful
reply, she said she was on her way again. Again, many thanks for
your prompt reply and complete assistance.
I don't have a question, but I think that what you are doing is great.
In NY state we take a test at the end of the year called a "regents"
exam. This one test determines if we pass or fail the course. Well,
I have a math regents in 9 hours, and I really needed help with
permutations and combinations, and you helped me. So I want
to say thank you, and keep up the good work. =)
From: Kristen A Long
Subject: Re: SAT Algebra Question
Dear Dr. Daniel,
Thank you very much for your time. It is reassuring to know that
whenever I get really stumped on a math problem (especially in the
summer and there are no available math teachers at my high school)
I can ask someone who knows exactly what they're talking about.
You are providing a wonderful service. Also, thank you for the
SAT tips. I'll do my very best!
From: Lamont R. Chestnut
Subject: Letter of Thanks
Thanks for helping me renew my 10-year-old daughter's faith in
finding answers to educational subjects on the Internet. Tonight
we both were stuck on the proper way to add and multiply fractions.
We have it down pat now. Thanks once again.
Lamont R. Chestnut
From: Todd Lloyd
Subject: Thank you for your help
Thank you for your help. My 10-year-old daughter asked me a question
about prime vs. composite numbers. Your answer was just the ticket.
From: Keir H. Larock
Subject: THANK YOU SO VERY MUCH!!
This is just a little note of extreme thanks. You have been both
prompt and attentive, and I thank you for it. The world needs more
people who take the time to help others. Thanks again,
Keir H. Larock
I have been searching for someone or some program to teach me
Algebra at the beginning levels for weeks now. I am so excited to
tell you that for the first time I understood algebra or at least
the first basic problem 6x (4 + 3) . Thank you.
From: Aimee Smith
Subject: Fwd: what a cool place
I'm a trig teacher who was out browsing and found your site. What
a fantastic resource! My students are going to be deluged with
printouts tomorrow to questions that I have forgotten to answer or
that I have found absolutely fascinating. Wonderful job you are
Subject: Thank-you for Dr. Math
Dear Dr. Math,
This is not a question, but a comment. I have been struggling with
my daughter, who is in the 4th grade. She can do division in her
head but struggles with the long division and putting it down on
paper. Thanks to a teacher online - she sent me your link, and
now with the graphics and step-by-step simple instructions I have
found I do believe my daughter will be fine. I much appreciate your
efforts to simplify the process so that children can continue
learning. I am very grateful to you and will continue using this
wonderful site very much in the future.
EVE2158 (Concerned Parent)
From: Arthur A. Molitierno
Subject: Thanks for the math formula
Dear Dr. Math,
As one who seldom uses mathematical formulae, I just wanted to thank
you for the site and for the clarity of the illustration of how to
figure percentage increases. It saved me from indicating my ignorance
to colleagues and solved my problem. If I can understand the illustration,
surely kids in the grade schools can too.
Best regards to keep counting and figuring,
Art - English Department
From: Tim Gibbons
Subject: Friends across "The Pond"
I need to say "thank you" for the third year running.
I really just want to say I can't thank you enough for your time and
effort and the very speed with which you responded again. It is so, so
gratifying I'm genuinely moved. You don't know me from Adam, as we say -
which means you have no reason to be so helpful and so generous, and
there's nothing in it for you.
These are controversial times when the Internet is creating so much
adverse feeling. The privacies and sensitivities of people are so often
abused by mischievous and sometimes evil people, hiding behind the
anonymity of the computer. To be treated in so friendly a manner and
to be given so much assistance on what many people would dismiss as a
trivial matter, is positively uplifting.
If this eulogizing of mine sounds rather excessive, I don't wish it to -
you've transformed my mood - the better side of human nature is still out
there, alive and kicking! And it's smiled on me when I asked it to.
That's how you've made me feel... and I'm going to be telling everyone
about it for the next few days, just as I did last year, and the year