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Dr. Math FAQ:
3D and higher
Browse Middle School History/Biography
Stars indicate particularly interesting answers or
good places to begin browsing.
Selected answers to common questions:
About Roman numerals.
- Measuring the Circumference of the Earth [08/16/1999]
How did Eratosthenes use a mathematical formula to prove the earth is
- Memory Aid for Roman Numerals [05/10/2000]
What number is XLIII? Do you have a way of remembering what letter equals
- Millennium and the Year 0 [01/03/1999]
I know that they new millennium really begins in 2001 because there was
no year 0. Why did they skip that year in the numbering?
- A Mule and a Donkey [04/08/1999]
A famous Euclidean brainteaser.
- Names of Polynomials [05/22/1999]
Why is an equation having only two roots, one of which is raised to the
second power, called a quadratic equation?
- Naming Large Numbers [06/05/2002]
In Rowlett's site for naming large numbers, he seems to take every
American prefix and bump its meaning by one to get the corresponding
Greek-based prefix. Why?
- Naming Small Numbers [07/29/2002]
Why were the names 'one', 'two', 'three', and so on, given to those
- Naming the Isosceles Triangle [09/23/1998]
How did the isosceles triangle receive its name?
- Negative Number History [11/25/2001]
What happened in the 16th century that caused people to need to use
negative numbers, and what was their image of a negative number before
- The New Math [07/05/2000]
What is the "New Math?"
- Number of Days in a Month [10/21/2000]
Why can't all months of the year have the same number of days?
- Number Systems: Two Points of View [06/30/1998]
What are the number systems?
- Number Word Etymologies [05/03/2001]
Who made up the names for numbers?
- Numeral Systems and Representing Numbers [10/30/1998]
Can you tell me the different ways the number 8 is represented? For
example, what about different numeral systems?
- Omar Khayyam [01/19/1997]
I need three events about Omar Khayyam, a 1st century mathematican, for a
high school report.
- One Plus One [04/11/1997]
Are you sure that 1 plus 1 equals 2?
- Origin of Algebra [9/14/1996]
Who found or used algebra first?
- Origin of math [1/6/1995]
1. Where did math originate? 2. Who thought of the term math? 3. When did
people decide to have math as a class in school? 4. Was the subject math
an accident or did someone sit down and actually think about it? 5. Where
did the word polygon come from?
- The Origin of Month Names [10/17/1998]
If oct is the prefix for 8 and dec is the prefix for 10, why is October
the 10th month and December the 12th month?
- Origin of Net View [05/14/2002]
We are studying the volume of pyramids and my students were
interested as to why the 'exploded' look at the pyramid was called
the net view.
- Origin of the 360-Degree Circle [11/10/1999]
Did the Babylonians discover the 360-degree circle?
- Origin of the Infinity Symbol [1/20/1995]
I need to find the origin of the math symbol for infinity that is used
- Origin of the Quadratic Equation [7/12/1996]
Who discovered the Quadratic Equation?
- Origin of the Terms Sine, Cosine, Tangent, etc. [10/27/1999]
Can you tell me the origin of the terms hypotenuse, sine, cosine, and
tangent? Can you tell me how the trigonometric formulas for sine, cosine,
and tangent came about?
- Origin of the Term Vertical Angles [04/04/2005]
Why do we call them "vertical angles" when many of them are "horizontal" (extending left and right)? Where did that name come from?
- Origins of Names of Ordinal and Cardinal Numbers [05/15/2002]
Which came first, ordinals or cardinals?
- Origins of the Fahrenheit Scale [11/20/1998]
Why did Fahrenheit choose 32 as the freezing point of water? Where did he
get his scale?
- Perpetual Calendar [10/21/1998]
How do you figure the perpetual calendar?
- Plus and Minus Signs [08/14/2002]
What is the difference between the two signs ± and minus over the plus
- Polygon Names II [12/11/2003]
Why is the triangle named "triANGL"', unlike all the other polygons, which have names like "quadriLATERAL" or "pentaGON"?
- Practical Applications of Negative Numbers [10/13/2002]
Why were negative numbers invented?
- President Garfield and the Pythagorean Theorem [3/7/1995]
I know that one proof of the Pythagorean Theorem was done by James
Garfield, before he became President of the United States. Can you give
me any more information?
- Quadratic Formula, Distributive Property [06/02/1997]
Who invented the quadratic formula?
- Questions About Math [07/31/1999]
Why was the Cartesian plane invented? Were the more abstract branches of
math developed just for fun? What is chaos theory? Why isn't Einstein's
equation e = mc^3?
- Ramanujan and a Formula for 1/Pi [04/06/1998]
Who is the man who knew infinity?
- Resources for Math History [10/24/1995]
Can you please help a grade 7 student with a research project on the
history of basic math - the origins of numbers, counting, the people who
first used or discovered these, and how they affected civilization?
- Rhind Papyrus Problems [03/23/1999]
What equations were on the Rhind Papyrus?
- Roman Counting Instruments [04/24/1998]
Could you describe some of the early counting instruments developed by
- Roman Numeral [7/10/1996]
Why does the Roman numeral D stand for 500?
- Roman Numerals: Division [11/05/2001]
I have found information on how to add and multiply Roman numerals, but
have not found any information on how to divide or subtract.