Advertisement.

EnchantedLearning.com is a user-supported site.
As a bonus, site members have access to a banner-ad-free version of the site, with print-friendly pages.
Click here to learn more.

ad
(Already a member? Click here.)


Our subscribers' grade-level estimate for this page: 4th

+, -
EnchantedLearning.com
Math Dictionary
x, ÷
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
o in Morse Code 
O is for ...
o in Braille


obelisk

An obelisk is a tall, four-sided tower topped with a pyramid.


oblique

Lines or planes are oblique when they are neither parallel nor perpendicular to each other.


obtuse angle

An obtuse angle is an angle greater than ninety degrees.


obtuse triangle

One of the interior angles of an obtuse triangle is obtuse ( an obtuse angle is over 90 degrees).


octadecagon

An octadecagon is an eighteen-sided figure.


octagon

An octagon is an eight-sided figure. Stop signs are octagons.


octahedron

An octahedron is an eight-sided geometric solid (a 3-D object).
1, 3, 5, 7, 9, 11, ...

odd number

An odd number is not divisible evenly by two.


one

One is the number between zero and two. One is the multiplicative identity, since one times any number is equal to that number.
1/2
one half

When something is divided into two equal parts, each of these two parts is one half of the original object.


operation

An operation is a rule for taking one or two numbers as inputs and producing a number as an output. Some arithmetic operations are multiplication, division, addition, and subtraction.


opposites

Opposites are things that are very, very different from each other. Some examples of opposites are: positive and negative, add and subtract, left and right, big and small, up and down.
orb

orb

An orb is a ball-shaped object.


order of magnitude

The order of magnitude is the estimate of size (or magnitude) expressed as a power of ten. For example, a 100 ft (102 ft) tall building one order of magnitude taller than a 10 ft (101 ft) tall building.


order of operations

In mathematical operations, the standard order of operations is: Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction. Within a category, operations are done from left to right.


ordinal number

Ordinal numbers show order. Some ordinals are first (1st), second (2nd), third (3rd), fourth (4th), fifth (5th), sixth (6th), seventh (7th), eighth (8th), ninth (9th), tenth (10th), eleventh (11th), twelfth (12th), etc.


ordinate

Ordinate is another name for numbers on the y-axis (the vertical axis). The ordinate is the second number in a point (x,y).
coordinates

origin

The origin is the point (0,0) -- where the x and y axes meet. In a 3-d coordinate system, the origin is the point (0,0,0) -- where the x, y and z axes meet.


ounce

An ounce is a unit of measure. Eight ounces are one cup.


oval

An oval is an egg-shaped figure.

+, -
EnchantedLearning.com
Math Dictionary
x, ÷
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Counting Addition Subtraction Multiplication Division
Number Line Fractions Decimals Graphs Measurement Rounding

Click on an underlined word for more information on that subject. If the math term you are looking for is not in the dictionary, please e-mail us.


Enchanted Learning®
Over 35,000 Web Pages
Sample Pages for Prospective Subscribers, or click below

Overview of Site
What's New
Enchanted Learning Home
Monthly Activity Calendar
Books to Print
Site Index

K-3
Crafts
K-3 Themes
Little Explorers
Picture dictionary
PreK/K Activities
Rebus Rhymes
Stories
Writing
Cloze Activities
Essay Topics
Newspaper
Writing Activities
Parts of Speech

Fiction
The Test of Time

Biology
Animal Printouts
Biology Label Printouts
Biomes
Birds
Butterflies
Dinosaurs
Food Chain
Human Anatomy
Mammals
Plants
Rainforests
Sharks
Whales
Physical Sciences: K-12
Astronomy
The Earth
Geology
Hurricanes
Landforms
Oceans
Tsunami
Volcano
Languages
Dutch
French
German
Italian
Japanese (Romaji)
Portuguese
Spanish
Swedish
Geography/History
Explorers
Flags
Geography
Inventors
US History

Other Topics
Art and Artists
Calendars
College Finder
Crafts
Graphic Organizers
Label Me! Printouts
Math
Music
Word Wheels

Click to read our Privacy Policy

E-mail


Enchanted Learning Search

Search the Enchanted Learning website for:



Advertisement.

Advertisement.


Copyright ©2004-2018 EnchantedLearning.com ------ How to cite a web page