1. Fifth Grade
Math Vocabulary

2. Diameter The distance across a circle through the center
Any chord of a circle that passes
through the center
Examples

3. 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(7+4)=(3)(7)+(3)(4)
10*(2+18)=(10*2)+(10*18)

4. Edges A line segment where 2 faces of a 3-dimensional figure meet
Examples
edge
edges
             

5. Equation (Modeling) X 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 X
X=2
X = 4
x + 4 = 5
x = 1

6. 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 =
Expanded form
935 = ,579 = 1,

7. A flat side of a 3-dimensional figure
Faces
A flat side of a 3-dimensional figure
Examples
face
faces

8. A fraction whose numerator is greater than or equal to its denominator
Improper Fraction
A fraction whose numerator is greater than or equal to its denominator
Examples
Improper fraction

9. Lines that meet or cross at one common point
Intersecting Lines
Lines that meet or cross at one common point
Examples P
Lines EF and GH intersect at point P
The two lines intersect at point (-2,1)

10. Inverse Operations Operations that undo each other Examples
Addition and subtraction are
inverse operations
(undo adding 3 by subtracting 3)
Multiplication and division are
(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

11. Given six test scores: 85,87,78,88,88 and 96
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 :

12. Metric Units: meter, liter, gram
Units developed in Europe and used in most of the world
Examples
2 liter bottles
   Quantity
         Unit
Equivalent
       Symbol
      length
        meter
3.28 feet
          m
      mass
        gram 
33.8 fl ounces
          g
     volume
         liter
.035 ounces
           l

13. Millions The unit between thousands and billions One million is
Examples
The unit between thousands and billions
One million is
One million seconds
= hours
9, ,
Nine million,
eight hundred seventy six thousand,
five hundred forty three.
One million pennies

14. Mixed Numbers A number that combines both
a whole number and a fraction

15. Parallel Lines Lines that never cross
and are always the same distance apart
They have the same slope
Examples

16. Lines which intersect to form a right (90 degree) angle
Perpendicular Lines
Lines which intersect to form a right (90 degree) angle
Examples

17. Plane A flat surface extending in all directions
A two-dimensional figure
Examples
Coordinate Plane

18. Polygon: regular/irregular
A closed plane figure for which all sides are straight line segments
Regular polygons have congruent sides and angles
triangle
square
hexagon
heptagon
pentagon
octagon
nonagon
Irregular polygons
decagon

19. Proper Fraction is less than its denominator
A fraction whose numerator
is less than its denominator
Examples

20. A polygon with four sides and four angles
Quadrilateral
A polygon with four sides and four angles
Examples

21. Radius
A line segment that connects the center of the circle to a point on the circle
Examples

22. 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

23. Standard Form
A way to write numbers by using the digits 0-9, with each digit having a place value
Exponential form
Standard form = x +
Standard form
Expanded Form

24. 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
One Thousandth

25. 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

26. 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

27. A quantity that can change or that may take on different values
Variable
A quantity that can change or that may take on different values
Examples x y 4 1 3 2

28. Vertex (or vertices) A corner point of a geometric figure
A point where two sides of a polygon intersect
Examples
Vertices

29. 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
X-axis
Y-axis
y-axis
x-axis