1. COORDINATE PLANE The plane containing the "x" axis and "y" axis.
MATH
Grades 6-8
Unit 4
COORDINATE PLANE
Definition:
The plane containing the "x" axis and "y" axis.
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2. X-COORDINATE Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
Definition:
The horizontal value in a pair of coordinates: how far along the point is.  The X Coordinate is always written first in an ordered pair of coordinates (x,y), such as (12,5).
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In this example, the value "12" is the X-Coordinate.

3. Y- COORDINATE Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
Definition:
The vertical value in a pair of coordinates. How far up or down the point is.  The Y Coordinate is always written second in an ordered pair of coordinates (x,y) such as (12,5).
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In this example, the value "5" is the Y Coordinate.

4. QUADRANT Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
QUADRANT
Definition:
Any of the 4 areas made when we divide up a plane by an x and y axis (as shown). They are usually numbered I, II, III and IV.
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5. ORDERED PAIR Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
Definition:
Two numbers written in a certain order.  Usually written in parentheses like this: (4,5)  Can be used to show the position on a graph, where the "x" (horizontal) value is first, and the "y" (vertical) value is second.
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Here the point (12,5) is 12 units along, and 5 units up.

6. ORIGIN Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
ORIGIN
Definition:
The starting point. On a number line it is 0. On a two-dimensional graph it is where the X axis and Y axis cross. In three dimensions it is the point (0, 0, 0).
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The origin is marked (0, 0) on the graph above.

7. X-AXIS Picture: Definition: Example:
MATH
Grades 6-8
Unit 4
X-AXIS
Definition:
The line on a graph that runs horizontally (left-right) through zero. It is used as a reference line so you can measure from it.
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8. Y-AXIS Picture: Definition: Example:
MATH
Grades 6-8
Unit 4
Y-AXIS
Definition:
The line on a graph that runs vertically (up-down) through zero. It is used as a reference line so you can measure from it.
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9. SUPPLEMENTARY Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
SUPPLEMENTARY
Definition:
Two Angles are Supplementary when they add up to 180 degrees. They don't have to be next to each other, just so long as the total is 180 degrees.
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60° and 120° are supplementary angles. 93° and 87° are supplementary angles.

10. COMPLEMENTARY Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
COMPLEMENTARY
Definition:
Two Angles are Complementary when they add up to 90 degrees (a Right Angle).  They don't have to be next to each other, just so long as the total is 90 degrees.
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Example:
60° and 30° are complementary angles. 5° and 85° are complementary
angles.

11. VERTICAL Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
VERTICAL
Definition:
In an up-down position. Upright.
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Trees grow in a vertical direction.

12. ADJACENT Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
ADJACENT
Definition:
Lying next to each other.
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Here a and b are adjacent angles.

13. CONGRUENT Picture: Definition: Example: MATH Unit 4 Grades 6-8
The same shape and size.  Two shapes are congruent when you can Turn, Flip and/or Slide one so it fits exactly on the other.
Angles are congruent when they are the same size (in degrees or radians). Sides are congruent when they are the same length.
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In this example the shapes are congruent (you only need to flip one over and move it a little).

14. POLYGON Picture: Definition: Example: Triangles Rectangles Pentagons
MATH
Grades 6-8
Unit 4
POLYGON
Definition:
A plane shape (two-dimensional) with straight sides.
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Example:
Triangles
Rectangles
Pentagons

15. CIRCLE Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
CIRCLE
Definition:
A 2-dimensional shape made by drawing a curve that is always the same distance from a center.
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16. CIRCUMFERENCE Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
CIRCUMFERENCE
Definition:
The distance around the edge of a circle (or any curvy shape).  It is a type of perimeter.
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17. RADIUS Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
RADIUS
Definition:
The distance from the center to the circumference of a circle It is half of the circle's diameter.
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18. DIAMETER Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
DIAMETER
Definition:
A straight line going through the center of a circle connecting two points on the circumference.
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19. AREA Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
AREA
Definition:
The size of a surface. The amount of space inside the boundary of a flat (2-dimensional) object such as a triangle or circle.
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Example:
These shapes all have the same area of 9.

20. VOLUME Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
VOLUME
Definition:
The amount of 3-dimensional space an object occupies.
Capacity.
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Metric: cubic centimeters (cm3), cubic meters (m3), liters US Standard: fluid ounce, cubic inch, cubic foot, pints, gallons

21. PRISM Picture: Definition: Example: MATH Unit 4 Grades 6-8
A solid object with two identical ends and flat sides: • The sides are parallelograms (4-sided shape with opposites sides parallel) • The cross section is the same all along its length The shape of the ends give the prism a name, such as "triangular prism" It is also a polyhedron.
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22. CYLINDER Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
CYLINDER
Definition:
A solid object with: • two identical flat ends that are circular or elliptical • and one curved side. It has the same cross-section from one end to the other.
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23. CENTRAL TENDENCY Picture: Definition: Example: MATH Unit 4 Grades 6-8
 Refers to the "middle" value or perhaps a typical value of the data, and is measured using the mean, median, or mode.
It may also be called a center or location of the distribution.
Measures of central tendency are often called averages.
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24. MEAN Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
MEAN
Definition:
The mean is the average of the numbers: a calculated "central" value of a set of numbers.  To calculate: Just add up all the numbers, then divide by how many numbers there are.
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What is the mean of 2, 7 and 9? Add the numbers: = 18 Divide by how many numbers (i.e. we added 3 numbers): 18 ÷ 3 = 6 So the Mean is 6

25. MEDIAN Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
MEDIAN
Definition:
The middle number (in a sorted list of numbers).  To find the Median, place the numbers you are given in value order and find the middle number.
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Example:
Find the Median of {13, 23, 11, 16, 15, 10, 26}. 
Put them in order: {10, 11, 13, 15, 16, 23, 26}
The middle number is 15, so the median is (If there are two middle numbers, you average them.)

26. MODE Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
MODE
Definition:
The number which appears most often in a set of numbers. 
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Example:
In {6, 3, 9, 6, 6, 5, 9, 3} the Mode is 6 (it occurs most often).

27. OUTLIER Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
OUTLIER
Definition:
A value that "lies outside" (is much smaller or larger than) most of the other values in a set of data.
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For example in the scores 25, 29, 3, 32, 85, 33, 27 & 28 both 3 and 85 are "outliers".

28. VARIANCE Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
VARIANCE
Definition:
The Variance is a measure of how spread out numbers are It is the average of the squared differences from the Mean.
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29. HISTOGRAM Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
HISTOGRAM
Definition:
A graphical display where the data is grouped into ranges (such as "40 to 49", "50 to 59", etc), and then plotted as bars. Similar to a Bar Graph, but in a Histogram each bar is for a range of data.
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30. PROBABILITY Picture: Definition: Example: MATH Unit 4 Grades 6-8
Probability is the chance that something will happen - how likely it is that some event will happen. Sometimes you can measure a probability with a number like "10% chance of rain", or you can use words such as impossible, unlikely, possible, even chance, likely and certain. 
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Example:
"It is unlikely to rain tomorrow.”

31. COMPOUND EVENTS Picture: Definition: Example: MATH Unit 4
Grades 6-8
Unit 4
Definition:
In the world of probability, compound events are probabilities of two or more things happening at once.
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32. FREQUENCY Picture: Definition: Example: MATH Unit 4 Grades 6-8
How often something happens (usually during a period of time). On the right is a heartbeat with a frequency of 78 beats per minute.
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