Math Vocabulary List
#1-10
Sum: the total or whole amount. Addend + Addend = Sum
Difference: difference between two numbers.
Associative property of addition: in addition, no matter how the numbers are grouped,
the answer will always be the same.
Commutative property of addition: in addition, numbers may be added together in any
order.
Identity of property of addition: when zero is added to a number the result is the
number itself.
Distributive property of addition: the sum of two numbers times a third number is
equal to the sum of each addend times the third number.
Expanded form: a way of writing numbers to show place value.
Word form: writing numbers using words.
Equal sign: used to show equivalence.
Value: numerical worth or amount.
#11-20
Equation: mathematical statement containing an equal sign, to show that two
expressions are equal.
Operations: there are four basic operations in arithmetic used to solve problems. They
are addition, subtraction, multiplication, and division.
Regroup: used to assist when trading or carrying in addition and subtraction.
Inverse operation: opposite, reverse operations. Addition and subtraction are inverse
operations. Multiplication and division are inverse operations.
Product: the result when two numbers are multiplied.
Quotient: the number resulting from dividing one number by another.
Factor: a whole number that divides exactly into another number or a whole number that
multiplies with another number to make a third number.
Multiple: a mathematical operation where a number is added to itself a number of times.
Zero property of multiplication: the product of zero and any number is zero.
Associative property of multiplication: the way factors are grouped does not change a
product.
21-30
Commutative property of multiplication: when two numbers are multiplied together,
the product is the same regardless of the order of the factors.
Identity property of multiplication: when a number is multiplied by 1 the result is the
number itself.
Distributive property of multiplication: multiplying a number is the same as
multiplying its addends by the number, then adding the products.
Stem and leaf plot: a data display that shows groups of data arranged by place value.
Mean: average of a number of different amounts. Add up all the amounts then divide
your total by how many amounts there were.
Median: the middle value of an ordered set of values.
Mode: in a set of scores, the mode is the score that occurs the most.
Range: subtract the highest and the lowest values to find the range of the set of numbers.
Convert: changing from one unit of measure to another.
Number expression: mathematical sentence written in numerals and mathematical
symbols.
#31-40
31. Transformation: a change in position or size.
32. Rotation: to turn an object.
33. Reflection: to flip an object.
34. Translation: to slide an object.
35. Similar: having the same shape but not necessarily the same size.
36. Congruent: having the same shape and the same size.
37. Net: flat shape which can be folded up into a three dimensional solid.
38. Benchmark numbers: a number used to estimate the size of other numbers. 0, ½, 1
39. Line: a long, thin mark that goes on forever in both directions.
40. Line segment: section of a line with two endpoints.
#41-50
41. Angle: to rays meeting at a common point.
42. Ray: line that has a starting point but no endpoint.
43. Parallel lines: lines exactly the same distance apart and never touch.
44. Perpendicular lines: lines that intersect at right angles to each other.
45. Intersecting lines: cross over one another at a point.
46. Horizontal lines: lines that run left and right.
47. Vertical lines: lines that run up and down.
48. Lines of symmetry: lines that divide objects in half so each side exactly mirrors the
other.
49. Coordinate grid: a plane containing an x axis and y axis.
50. Ordered pairs: a point on a coordinate grid. (x,y)
#51 - 60
51. Equivalent: having the same value or amount.
52. Numerator: number above the line of a fraction, represents the part of the whole.
53. Denominator: bottom number in a fraction, represents the whole.
54. Decimal: fraction of a number.
55. Area: the size a surface takes up.
56. Perimeter: distance around the outside of a shape.
57. Estimate: rounding a number.
58. Justify: to prove what you say and do is right.
59. Diagram: representation of information.
60. Variable: a letter or symbol representing a varying quantity.
# 61 - 70
61. Accurate: to find a solution without error
62. Chart: visual representation of data
63. Coordinate grid: a plane containing an x axis and y axis
64. Data: Factual information, especially information organized used to reason or make
decisions.
65. Equation: a mathematical statement that two expressions are equal
66. Estimate: To calculate approximately
67. Expand: To write as a sum of terms in an extended form
68. Factor: One of two or more quantities that divides a given quantity without a remainder
69. Identity of property of addition: when zero is added to a number the result is the
number itself.
70. Justify: to show an solution to be reasonable
71. Label: To identify
72. Mode: in a set of scores, the mode is the score that occurs the most
73. Range: subtract the highest and the lowest values to find the range of the set of
numbers
74. Sum: the total or whole amount