See also the
3D and higher
Browse Middle School Definitions
Stars indicate particularly interesting answers or
good places to begin browsing.
- Definition of Vinculum [10/21/2004]
Is the bar placed over the set of repeated digits in a repeating
decimal called a vinculum? I've heard that but I can't confirm it.
- Definitions: Average, Mean, Mode [5/20/1996]
Arithmetic, geometric, harmonic means defined.
- Definitions of Cones and Cylinders [03/02/2004]
Are cones and cylinders pyramids, prisms or neither? My 5th grade
geometry class cannot reach an agreement on this subject!
- Definitions of Range [10/20/2003]
I can find only one definition of range in the math dictionaries -
the difference between the smallest and the largest number in a set.
We are always talking about 'They range in age from, or they range in
height, or they range in weight, or they range in size, etc'. If
the only defintion of range is the difference, why do we say 'They
- Degrees and Radians, Explained [03/19/2002]
How do you find the degree measure for an angle from pi/60 rad?
- Degrees in a Sphere? Steradians [09/27/2001]
If one can say that a circle contains 360 degrees, how many degrees can
one say are in a sphere?
- The Degree Symbol [11/02/1998]
Do you know what the degree symbol stands for? What is its history?
- De Longchamp's Point [09/21/2000]
What is De Longchamp's point, and how is it used?
- Difference Between Math and Arithmetic [11/06/2001]
My students haven't heard the word arithmetic. No one seems to be able to
tell the difference, if there is one, between arithmetic and mathematics.
Is there a difference, and what is it?
- Difference between Oval and Ellipse [10/18/2001]
What is the difference between an oval and an ellipse? Am I right if I
say that "all ellipses are ovals, but all ovals cannot be ellipses"?
- Difference between Percent and Percentage [04/26/2008]
Is there any difference between percent and percentage?
- Dimensions [08/30/2001]
What are 1-dimensional, 2-dimensional, and 3-dimensional? What's the
- Division Symbols [10/23/1998]
What is the name of the symbol used in long division problems? What about
other division symbols?
- Do Circles Have Corners? [08/06/1999]
Can you have angles or corners without edges?
- Does 2k4 Mean 2004 or 2400? [01/10/2004]
On internet communities it is common to reduce figures using 'k' as a
shortcut; for example 2k is used instead of 2000. I was under the
impression that a number after the k (such as 2k4) meant 2400, and
that to get 2004 in this system you'd need to write 2k004. But I've
also seen 2k4 used for 2004. Which is correct? Does 2k4 mean 2004 or
- Does a Cone have an Edge? A Vertex? [03/12/2002]
Our 4th grade math textbook defines a cone as "A solid figure with one
circular face and one vertex." This sounds reasonable until you read the
textbook's definitions for face, edge, and vertex.
- Does a Sphere have Sides? [04/20/2001]
How many sides does a sphere have?
- Domain and Range of Functions [03/20/2003]
I am learning in school about the domain and range of functions. Why
are they called domain and range? And where did they come from?
- Edges vs. Corners [04/18/2002]
My students get confused on how to determine an edge versus a corner,
and counting the number of edges on a geometric figure, say a cube.
- Equable Rectangle [01/28/2001]
What is the formula for an equable rectangle if I have one side of the
- Equable Shapes [04/26/2001]
Is there a rule for how to get equable shapes, that is, shapes with the
same area and perimeter?
- Equals Sign with a Dot or a ~ Over It [01/25/2001]
What does an equals sign with a dot (.) over it mean?
- Equations Versus Formulas: Their Unknowns, Substitutions, and Solutions [03/12/2016]
A teen wonders if formulas have more unknowns than equations do; or if
you substitute into formulas, but solve equations. With examples
aplenty, Doctor Peterson clarifies and unpacks the terms.
- Equilateral, Isosceles, Scalene - Word Origins [12/09/2001]
I need to find out about the origins of the scalene, isoceles, and
equilateral triangles. How they were named?
- Etymologies of Algebra, Geometry, Trigonometry [10/22/2001]
What are the origins and roots of the words geometry, algebra, and
- Etymology of 'Logarithm' [03/19/1999]
How does the term 'logarithm' relate to the terms 'exponent' and 'knots',
and to nautical logbooks?
- Etymology of the Word Hypotenuse [01/26/2003]
Why is the hypotenuse called 'hypotenuse'?
- Etymology of the Word Mathematics [12/10/2001]
Why do you call maths maths?
- Etymology of the Word 'Quotient' [11/25/2002]
What is the origin of the word 'quotient'?
- Etymology of the Word Rectangle [02/07/2003]
Where does the word 'rectangle' come from?
- Etymology of the Word Rhombus [01/30/2003]
Where does the word rhombus come from?
- Euler Line [06/08/1998]
What is the Euler line?
- Examples and Explanations of Basic Properties of Equality [07/31/2004]
Can you explain the substitution, symmetric, and transitive properties
of equality in simpler terms?
- Explaining Independent and Dependent Variables [10/25/2002]
Can you elaborate on the definitions of independent and dependent
- Explorations of the Circle [02/09/1999]
What is the definition of a circle? How does it relate to pi? What are
the important parts of a circle?
- Exploring Estimation [08/29/2003]
If a rare truffle is $13.20 for 0.44 oz, estimate the cost of a whole
- Expressions: Of Simplest Terms [04/20/2015]
An adult wonders if even the most trivial term would qualify as an expression. Doctor
Peterson explains why it does, and reveals the thinking behind such an inclusive definition.
- Expressions vs. Equations, Explained [04/10/2011]
A student knows how to evaluate expressions and solve equations, but doesn't see the
difference between the two. Doctor Ian explains the distinction by way of an analogy to
phrases and sentences, illustrating throughout with examples, before leaving the
student with a mathematical statement for her to ponder further whether "an equation
is an expression with an equals sign."
- Expression vs. Equation [03/20/2003]
What is the difference between an expression and an equation?
- Factorials [2/3/1996]
What does 3! mean?