5th Grade Math Vocabulary

mixed number

A value that combines a whole number and a fractional amount

mode

In a group of values, the value that occurs most often.

horizontal

left to right; parallel to the horizon

ratio

A comparison of the two values of two numbers

prime number

A number with exactly two factors: the number itself and one.

rhombus

A parallelogram whose four sides and opposite angles are congruent.

rectangle

A parallelogram with four right angles

area

The amount of space inside a 2-dimensional figure

quotient

The answer to a division problem

product

The answer to a multiplication problem. The result of multiplying two or more factors.

difference

The answer to a subtraction problem.

denominator

The bottom number of a fraction; the total number of equal parts

range

The difference between the least and greatest values in a set of numbers.

circumference

The distance around a circle (the perimeter of a circle).

perimeter

The distance around a figure.

face

The flat surface of a polyhedron

least common multiple (LCM)

The smallest multiple that two or more numbers have in common

minimum

The smallest number in a set of data

mean

The sum of a group of numbers divided by the number of numbers. Also known as the average.

numerator

The top number of a fraction; how many parts of a whole or group are included in the fraction.

polygon

Three or more line segments in a plane that forms a closed figure. The line segments never cross but meet at their endpoints.

vertex (vertices - plural)

A Corner; point at which two line segments, lines, or rays meet to form an angle; point where three or more faces intersect

improper fraction

A fraction with a numerator that is larger than or equal to its denominator.

lowest terms

A fraction with all common factors (other than 1) factored out of the numerator and denominator

radius

A length that is half the diameter of a circle; the distance from the center to the outside of the circle

diameter

A line segment that passes through the center of a circle and has its endpoints on the circle. It describes how wide the circle is.

common factor

A number that is a factor of two or more numbers.

common denominator

A number that is a multiple of all denominators in a problem.

factor

A number that is multiplied by another number to find a product

quadrilateral

A polygon that has four sides.

hexagon

A polygon with six sides.

composite number

A positive whole number with more than two factors. In other words, a number that is not prime.

parallelogram

A quadrilateral with two pairs of congruent, parallel sides.

array

A rectangular arrangement of objects in rows and columns.

prism

A solid figure that has two congruent, parallel polygons as its bases. Its sides are parallelograms

translation

A transformation that moves all of the points of a figure the same distance in the same direction; a slide

reflection

A transformation that produces a mirror image of a figure; a flip

rotation

A transformation that turns a figure around a fixed point; a spin

equilateral triangle

A triangle with equal sides and equal angles.

right triangle

A triangle with one right angle

scalene triangle

A triangle with sides of different lengths and no two angles are the same.

square unit

A unit for measuring area

median

A value found by ordering a group of data from least to greatest and choosing the middle value of the group.

even number

A whole number ending with 0, 2, 4, 6, or 8 in the ones place.

odd number

A whole number ending with 1, 3, 5, 7, or 9 in the ones place.

integers

All whole numbers (both positive and negative) and zero.

acute angle

An angle measuing more than 0 degrees and less than 90 degrees

right angle

An angle that measures 90 degrees

obtuse angle

An angle with a measurement greater than 90 degrees but less than 180 degrees

octagon

An eight-sided polygon

prime factorization

Breaking down a composite number until all of the factors are prime

concentric circles

Circles that have the same center but radii of different lengths

estimate

Find an approximate answer for a problem. Round the numbers before working the problem.

equivalent

Having equal value

congruent

Having the same size and shape

parallel lines

Lines that do not intersect. //

perpendicular lines

Lines that meet or cross at right angles

addends

Numbers added together to find a sum.

area

Surface space that is measured in square units.

sum

The answer to an addition problem.

angle

The figure formed when two lines meet at a common endpoint called a vertex.

maximum

The largest number in a set of data

greatest common factor (GCF)

The largest single factor for two or more numbers.

probability

The likelihood that an event will occur.

capacity

The measure of the amount of a substance that a container will hold

divisor

The number by which a number is divided

dividend

The number to be divided in a division problem

percent

The ratio of a number to 100 (per one hundred). %

simplify

To make a fraction easier to work with by taking out common factors. To write in lowest terms.

vertical

straight up and down; perpendicular to the horizon