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Selected answers to common questions:
Meters squared or square meters?
Greater than, less than symbols.
- Are Negatives Factors of Other Numbers? [07/16/2003]
Are negative numbers factors of other numbers? Is -3 a factor of 3?
Is -3 a multiple of 3?
- Common Difference, Common Ratio [04/21/2003]
Differences in arithmetic and geometric sequences.
- Fraction Bar Name [12/14/1996]
What is the name of the little line that separates the divisor from the
dividend in a standard division question?
- Measurement: Precision vs. Accuracy [01/07/2003]
Using a metric ruler student A measured the length of an object to
the nearest tenth (0.1) of a centimeter, while student D measured its
length to the nearest centimeter. Which measurement is more accurate?
- Millimeters, Inches, Feet, Miles [07/10/2003]
The conversions given for millimeters to inches is 25.4, and for feet
to miles is 5280. Are these numbers exact?
- Multiplication's Multiple Meanings: Unified by the Distributive [01/01/2015]
Area? Matrix multiplication? Scaling and rotation? A parent seeks a global
understanding — or at least some internal consistency — as to what ties
together all the operations called "multiplication." Building up from the natural
numbers, where multiplication is repeated addition (MIRA), Doctor Peterson teases out two
- 2 Square Feet vs. 2 Feet Square [11/22/1998]
What is the difference between 2 square feet and 2 feet square?
- Abbreviation of Ounce [04/27/2002]
Why is the abbreviation for ounce oz.?
- Additive Identity and Other Properties [01/03/1999]
Can you explain the identity of zero and the commutative and
multiplicative properties? Why are they special?
- Adjacent Angles [09/19/2001]
What is the definition of adjacent angles?
- Age Classifications [08/24/2001]
I'm trying to complete a table for age classes (octogenarian = 80s,
nonagenarian = 90s, etc.).
- Angles: Acute, Right, Obtuse, Reflex [06/06/2001]
How can I remember what the names of angles mean?
- Associative, Distributive Properties [9/5/1996]
Please explain the associative and distributive properties.
- Average [05/10/2001]
Is it true that the average of a set of data is always computed by adding
all the numbers together and dividing by the total number?
- Basic Real Number Properties [07/31/1997]
I need information about basic real number properties: associative,
commutative, closure, identity, inverse, distributive.
- Bits (Money) [02/26/2001]
In the cheer: Two bits, four bits, six bits, a dollar; All for (school),
Stand up and holler! what are bits?
- Centimeters in a Hand [02/27/2002]
You measure horses in "hands." I need to know how many centimeters are in
- Circle Definitions [04/29/2002]
Define a circle and its parts: diameter, radius, center,
- Circumference vs. Perimeter [05/09/2003]
Technically speaking, can the term 'perimeter' apply to a circle in a
- Clarifying Percentages vs. Percentage Points [11/21/2003]
What is the difference between measuring using percentages versus
measuring using percentage points? What is meant by a percentage point?
- Clockwise and Counterclockwise [03/19/2001]
What does clockwise mean?
- The Commutative Property Around Us [11/24/1998]
Which operations are commutative... to put on your coat and to pick up
- Comparing Transitivity and Substitution [10/01/2003]
What is the difference between transitivity and substitution?
- Complementary or Supplementary? [04/02/2001]
I keep getting complementary and supplementary mixed up. How can I
remember which is which?
- Composite Numbers [1/30/1996]
What are Composite Numbers?
- Concave and Convex Polygons [08/13/2001]
What's the difference between a convex and a concave polygon?
- Congruent Fractions [04/03/1997]
What are congruent fractions?
- Defining a Sphere [12/1/1994]
We have two math textbooks from different years that give different information about spheres. One says a sphere has one curved face and the other says it has zero. Is one right and the other wrong or has the definition changed?
- Defining Decimal Numbers [07/01/2004]
An interesting look at how the idea of a 'decimal' number is widely
misunderstood and the word itself is used incorrectly.
- Defining Multiplication [08/16/2002]
What is the distinction between 3*4 and 4*3?
- Defining Multiplication, Redux [10/09/2014]
Parents, students, and teachers alike continue to wrestle with
distinctions between multipliers and multiplicands.
- Defining "Problem Solving" [07/30/2007]
Is there a clear definition of what "problem solving" means?
- Defining the Term Oblong [05/15/2000]
Can you give a definition of the term "oblong"?
- A Definition of Geometry [2/1/1996]
A fifth grader asks Dr. Math to give her a definition of geometry.
- Definition of Quotient [11/13/2008]
If I divide 15 by 2, I always thought that the quotient was 7 and the
remainder was 1. But I've seen that the quotient can also be 15/2. How
can quotient have different meanings?
- 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 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!
- Describing a Rhombus [01/17/1997]
What is a rhombus?
- Describing Patterns [10/23/2002]
What is a pattern?
- A Diamond Is Forever Unclear, As a Term — and How to Teach from That [12/17/2010]
A teacher wonders what the term "diamond" might mean mathematically. Emphasizing
that orientation does not enter into polygon classification, Doctors Ian and Rick each
suggest ways to take colloquial meaning, and ambiguity, as springboards to motivate
fertile discussion, noticing, and wondering.