7th Grade Math Vocabulary List

40. Equivalent ratios
Ratios whose fraction representations are equivalent are called equivalent ratios. For example, 3 to 4 and 6 to 8 are equivalent.

41. Image
The figure that results from some transformation of a figure.

42. Midpoint
A point that divides a line segment into two segments of equal length.

43. Scale factor
The number used to multiply the lengths of a figure to stretch or shrink it to a similar image. If we use a scale factor of 2, all lengths in the image are two times as long as the corresponding lengths in the original.

44. Similar
Similar figures have corresponding angles of equal measure and the ratios of each pair of corresponding sides are equivalent.

45. Supplementary angles
Supplementary angles are two angles that form a straight line. The sum of the angles is 180 degrees.

46. Coefficient
A number that is multiplied by a variable in an equation or expression . In a linear equation of the form y= mx + b, the number m is the coefficient of x as well as the slope of the line.

47. Function
A relationship between two variables in which the value of one variable depends on the value of the other variable. For example, the distance d in miles covered in t hours by a car traveling at 55 mph is given by the equation d= 55t. The relationship between distance and the time is a function.

48. Intersecting lines
Lines that cross or intersect.

49. Linear relationship
A relationship in which there is a constant rate of change between two variables; for each unit increase in one variable, there is a constant change in the other variable.

50. Origin
The point where the x- and y-axes intersect on a coordinate graph . With coordinates (0,0) the origin is the center of the coordinate plane.

51. Rise
The vertical change between two points on a graph. The slope of a line is the rise divided by the run.

52. Run
The horizontal change between two points on a graph. The slope of a line is the rise divided by the run.

53. Slope
The number that expresses the steepness of a line. The slope is the ratio of the vertical change to the horizontal change between any two points on the line. Often referred to as the rise over the run.

54. X-intercept
The point where a graph crosses the x-axis.

55. Y-intercept
The point where the graph crosses the y-axis. In a linear equation of the form y=mx + b, the y- intercept is the constant , or b.

56. Base
The face of a three-dimensional shape chosen to be the “bottom” face.

57. Cone
A three-dimensional shape with a circular base and a vertex opposite the base.

58. Cube
A three-dimensional shape with six identical square faces.

59. Cylinder
A three-dimensional shape with two opposite faces that are congruent circles. The side (lateral surface) is a rectangle that is “wrapped around” the circular faces at the ends.

60. Edge
A line segment formed where two faces of a three-dimensional shape meet.

61. Face
A flat two-dimensional surface of a three-dimensional shape.

62. Height
The vertical distance between the face chosen to be the base and
 A) The opposite face of a prism or cylinder, or
 B) The vertex of a cone or pyramid.

63. Net
A two-dimensional pattern that can be folded into a three-dimensional figure.

64. Prism
A three-dimensional shape with a top and bottom (base) that are congruent polygons and lateral faces that are parallelograms.

65. Pyramid
A three-dimensional shape with one polygonal base and lateral sides that are all triangles that meet at a vertex opposite the base.

66. Rectangular prism
A prism with a top and bottom (base) that are congruent rectangles.

67. Sphere
A three-dimensional shape whose surface consists of all the points that are a given distance form the center of the shape.

68. Surface area
The area required to cover a three-dimensional shape.

69. Volume
The amount of space occupied by, or the capacity of, a three-dimensional shape. The volume is the number of unit cubes that will fit into a three-dimensional shape.

70. Graph
A "picture" showing how certain facts are related to each other or how they compare to one another.

71. Inequality
Two or more sets of values that are not equal.
Example: 4<12, or 6≤ x ≥15.

72. Expression
A combination of variables , numbers, and symbols that represent a mathematical relationship .

73. Linear equation
An equation whose graph on a coordinate grid is a line. The equation can be written in the form y = mx + b.

74. Unknown
In algebra, the quantity represented by a variable.

75. Probability
The numerical measure of the chance that a particular event will occur, depending on the possible events. The probability of an event, P(E), is always between 0 and 1, with 0 meaning that there is no chance of occurrence and 1 meaning a certainty of occurrence.

76. Analyze
To breakdown a whole into component parts so that it may be more easily understood.

77. Conclusion
A statement that follows logically from other facts.

78. Justify
To prove or show to be true or valid using logic and/or evidence.

79. Validate
To determine, substantiate, verify, or confirm whether a given statement or argument passes specific standards.

80. Distribution
The arrangement of values in a data set. Data sets collected from observation or experiment.

81. Tree diagram
A strategy for determining the number of possible outcomes in a probability situation. The number of final branches is the equal to the number of possible outcomes.

82. Scatter plot
A graph of points (x,y), one for each item being measured, on a coordinate plane. The two coordinates of a point represent their observed, paired values. Example: The ordered pairs may relate temperature to time of day (time, temp).

83. Box-and-whisker plot
A graph which displays the following five points from a data set- the minimum value, the lower quartile (25th percentile), the median, the upper quartile (75th percentile), and the maximum value.
Example:

84. Stem-and-leaf plot
A method of organizing a list of numbers into stems and leaves where leaves represent units and stems represent the other digits. Stems are listed in increasing or decreasing order. Leaves are associated with their stem but need not be sequential.
Examples:

85. Measures of central tendency
Numbers that give some indication of the distribution of data. Three common measures of central tendency are mean, median, and mode.