Fifth Grade

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Fifth Grade Math Vocabulary
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Diameter
The distance across a circle through the center
Any chord of a circle that passes through the
center Examples
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Distributive Property
A number multiplying a sum in parentheses
multiplies each number and then adds the
products It gives the same result as adding
first and then multiplying A property which
multiplies a single term with two or more terms
inside a set of parentheses Examples 3 x (4
2) (3 x 4) (3 x 2)
3(74)(3)(7)(3)(4) 10(218)(102)(1018)
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Edges
A line segment where 2 faces of a 3-dimensional
figure meet Examples
             
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Equation (Modeling)
A mathematical sentence that shows that two
quantities are equal To solve an equation,
find a value for the variable
that makes the sentence true
Examples
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Expanded Form
Writing a number as the sum of the values of its
digits A way to write numbers by showing the
value of each digit Examples
935 900 30 5
1,579 1,000 500 70 9
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Faces
A flat side of a 3-dimensional
figure Examples
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Improper Fraction
A fraction whose numerator is greater than or
equal to its denominator Examples
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Intersecting Lines
Lines that meet or cross at one common
point Examples
Lines EF and GH intersect at point P
The two lines intersect at point (-2,1)
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Inverse Operations
Operations that undo each other Examples
Addition and subtraction are inverse
operations (undo adding 3
by subtracting 3) Multiplication
and division are inverse operations
(undo multiplying by 2 by dividing by
2) To solve an equation use inverse
operations x 3 5 x 3 3 5 3 x 2
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Mean
One of the measures of central tendency It is
found by adding the numbers in a data set and
then dividing by the number of data
points Example Given six test
scores 85,87,78,88,88 and 96 The mean or
average is 87
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Metric Units meter, liter, gram
Units developed in Europe and used in most of the
world Examples
   Quantity          Unit Equivalent        Symbol
      length         meter 3.28 feet           m
      mass         gram  33.8 fl ounces           g
     volume          liter .035 ounces            l
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Millions
Examples
One million seconds 277.76 hours
One million pennies
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Mixed Numbers
A number that combines both a whole number and a
fraction
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Parallel Lines
Lines that never cross and are always the same
distance apart They have the same
slope Examples
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Perpendicular Lines
Lines which intersect to form
a right (90 degree) angle Examples

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Plane
A flat surface extending in all directions A
two-dimensional figure Examples
Coordinate Plane
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Polygon regular/irregular
A closed plane figure for which all sides are
straight line segments Regular polygons have
congruent sides and angles
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Proper Fraction
A fraction whose numerator is less than its
denominator Examples
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Quadrilateral
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Radius
A line segment that connects the center of the
circle to a point on the circle
Examples
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Ray
A part of a line starting at a particular point,
its endpoint, that extends infinitely in one
direction Examples
An angle is made up of 2 rays
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Standard Form
A way to write numbers by using the digits 0-9,
with each digit having a place value
Exponential form
Standard form
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Thousandths
The place value that represents one thousandth
of a whole It is one tenth of a hundredth and
one hundredth of a tenth Examples
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Types of triangles (isosceles,equilateral,scalene
)
A scalene triangle has no congruent sides An
isosceles triangle has two congruent sides An
equilateral triangle has all three sides
congruent Examples
Scalene
Equilateral
Isosceles
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Types of triangles (right, acute, obtuse)
A right triangle has one right angle An acute
triangle has three acute angles An obtuse
triangle has one obtuse angle Examples
Acute triangle
Obtuse triangle
Right triangle
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Variable
A quantity that can change or that may take on
different values Examples
x y
0 4
1 3
2 2
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Vertex (or vertices)
A corner point of a geometric figure A point
where two sides of a polygon intersect Examples

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x-axis, y-axis
The x-axis is the horizontal number line, the
y-axis is the vertical number line, They form a
plane used for graphing points and
lines Examples
y-axis
x-axis