Fifth Grade Math Vocabulary

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

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)

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

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

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 200 + 70 + 3 = Expanded form 935 = 900 + 30 + 5 1,579 = 1,000 + 500 + 70 + 9

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

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

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)

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

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 :

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

Millions The unit between thousands and billions One million is Examples The unit between thousands and billions One million is One million seconds = 277.76 hours 9, 8 7 6, 5 4 3 Nine million, eight hundred seventy six thousand, five hundred forty three. One million pennies

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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