Math Vocabulary for 5th Grade

99 terms

JamWise Education Team·Updated March 2026

In 5th grade, students in the upper elementary (3-5) band encounter 99 essential math vocabulary terms. These words form the foundation for classroom discussions, reading comprehension, written assignments, and standardized assessments. Mastering this vocabulary gives students the language they need to express their understanding with clarity and confidence.

Below you will find every math term for 5th grade, organized by topic where applicable. Each term links to a detailed definition page with grade-level explanations, related vocabulary, and connections to JamWise learning resources.

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algebra

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Corresponding terms

Terms that have the same position in two related number patterns. In the patterns 0,3,6,9 and 0,6,12,18, the terms 6 and 12 correspond.

Equation

A mathematical sentence showing that two expressions are equal, using an equal sign. Example: 3x + 2 = 14.

Evaluate

To find the value of a mathematical expression by performing all the operations. Evaluating 3 + 4 x 2 gives 11.

Expression

A combination of numbers, variables, and operation symbols that represents a mathematical relationship, without an equal sign.

Inequality

A math sentence that compares two values using symbols like less than, greater than, or not equal to. Example: 5 + 3 is greater than 6.

Numerical expression

A math phrase made up of numbers and operation symbols but no equal sign. Example: (8 + 2) x 5.

Pattern

A sequence of numbers that follows a rule. In 1, 5, 25, 125 the rule is 'multiply by 5.'

Variable

A letter or symbol that represents an unknown number or a number that can change. In 5 + n = 12, n is a variable.

data

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Data

Facts, numbers, or measurements collected to analyze. Data can be shown in tables, charts, or graphs.

Line graph

A graph that uses points connected by line segments to show how data changes over time.

Line plot

A graph that uses marks above a number line to show how often values occur in a data set.

decimals

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Decimal

A number with digits to the right of a decimal point, showing values less than one whole. 3.75 has a whole part (3) and a decimal part (.75).

Decimal point

The dot in a decimal number that separates the whole-number part on the left from the fractional part on the right.

Equivalent decimals

Decimals that have the same value. 0.5, 0.50, and 0.500 are all equivalent because they represent the same amount.

Rounding decimals

Replacing a decimal with the nearest whole number, tenth, or hundredth. 3.47 rounds to 3.5 (nearest tenth).

Thousandths

The third place to the right of the decimal point. In 0.125, the 5 is in the thousandths place, meaning 5 out of 1,000 parts.

fractions

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Common denominator

A shared number used as the denominator when adding or subtracting fractions with different denominators.

Improper fraction

A fraction where the numerator is greater than or equal to the denominator, representing a value of 1 or more. 7/4 equals 1 and 3/4.

Mixed number

A number written as a whole number and a fraction together, like 3 and 1/2.

Simplest form

A fraction where the numerator and denominator have no common factor other than 1. The simplest form of 4/8 is 1/2.

Unit fraction

A fraction with a numerator of 1, such as 1/5 or 1/12. It represents exactly one equal part of a whole.

Unlike denominators

Fractions that have different bottom numbers, like 1/3 and 1/5. To add them, you need to find a common denominator first.

geometry

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Coordinate plane

A flat grid formed by two number lines that cross at a right angle — a horizontal x-axis and a vertical y-axis.

Cube

A special rectangular prism where all 6 faces are identical squares. Each edge is the same length.

Edge

The line segment where two faces of a 3D shape meet. A cube has 12 edges.

Face

A flat surface on a 3D shape. A rectangular prism has 6 faces, and each face is a rectangle.

Hierarchy

A system of classification organized from general to specific. In geometry, a square is a special rectangle, which is a special parallelogram.

Ordered pair

Two numbers written in parentheses that name a point on a coordinate plane. In (3, 5), go right 3 and up 5.

Origin

The point where the x-axis and y-axis cross on a coordinate plane, written as (0, 0).

Parallelogram

A quadrilateral with two pairs of parallel sides. Opposite sides are equal in length.

Polygon

A closed flat shape made of straight line segments. Triangles, quadrilaterals, pentagons, and hexagons are all polygons.

Polyhedron

A 3D shape where all the faces are flat polygons. Cubes, prisms, and pyramids are polyhedra. Spheres and cones are not.

Prism

A 3D shape with two identical, parallel polygon faces (called bases) connected by rectangular sides.

Pyramid

A 3D shape with a polygon base and triangular faces that meet at a single point (apex) at the top.

Quadrilateral

Any polygon with exactly four sides and four angles. Squares, rectangles, parallelograms, rhombuses, and trapezoids are all quadrilaterals.

Rectangular prism

A 3D shape with 6 rectangular faces, like a cereal box or a brick. Its volume equals length times width times height.

Rhombus

A parallelogram with four sides that are all the same length. A square is a special rhombus with right angles.

Solid figure

Another name for a three-dimensional shape. Solid figures have length, width, and height, unlike flat shapes.

Three-dimensional

A solid shape with length, width, and height. Cubes, spheres, and pyramids are 3D shapes — they take up space.

Trapezoid

A quadrilateral with exactly one pair of parallel sides.

Two-dimensional

A flat shape with only length and width and no thickness — like a drawing on paper. Circles, triangles, and rectangles are 2D.

Vertex

The point where two or more edges of a 3D shape meet, or where two sides of a polygon meet. A cube has 8 vertices.

X-axis

The horizontal number line on a coordinate plane that runs left and right.

X-coordinate

The first number in an ordered pair. It tells how far to move right or left from the origin on the x-axis.

Y-axis

The vertical number line on a coordinate plane that runs up and down.

Y-coordinate

The second number in an ordered pair. It tells how far to move up or down from the x-axis on the y-axis.

measurement

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Cubic unit

A small cube with edges that are each 1 unit long, used to measure volume.

Customary system

The measurement system used in the United States, with inches, feet, miles for length; cups, pints, gallons for capacity; and ounces, pounds for weight.

Formula

A mathematical rule expressed with symbols. The formula for volume of a rectangular prism is V = l x w x h.

Gallon

A large unit of liquid measurement in the customary system. 1 gallon equals 4 quarts. A big milk jug holds 1 gallon.

Kilogram

A unit of mass in the metric system. 1 kilogram equals 1,000 grams — about as heavy as a pineapple.

Kilometer

A unit of length in the metric system. 1 kilometer equals 1,000 meters — about four times around a school track.

Metric system

A system of measurement based on multiples of 10 that uses meters for length, liters for capacity, and grams for mass.

Milligram

A very tiny unit of mass in the metric system. 1,000 milligrams equals 1 gram. A grain of sand weighs about 1 milligram.

Milliliter

A very small unit for measuring liquid in the metric system. 1,000 milliliters equals 1 liter. An eyedropper holds about 1 milliliter.

Millimeter

A very small unit of length in the metric system. 10 millimeters equals 1 centimeter. The thickness of a dime is about 1 millimeter.

Ounce

A small unit of weight in the customary system. 16 ounces equals 1 pound. A slice of bread weighs about 1 ounce.

Pound

A unit of weight in the customary system. 1 pound equals 16 ounces. A loaf of bread weighs about 1 pound.

Quart

A unit of liquid measurement in the customary system. 1 quart equals 2 pints or 4 cups.

Surface area

The total area of all the faces of a 3D shape. To find it, calculate the area of each face and add them together.

Ton

A very large unit of weight in the customary system. 1 ton equals 2,000 pounds — about as heavy as a small car.

Unit cube

A cube with sides that are each exactly 1 unit long. Unit cubes are used to measure volume.

Volume

The amount of space inside a 3D shape, measured in cubic units. A box 3 units long, 2 wide, and 4 tall has a volume of 24 cubic units.

operations

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Braces

The symbols { } used as a third level of grouping in complex expressions, outside brackets and parentheses.

Brackets

The symbols [ ] used to group numbers in an expression, usually around parentheses to show a second level of grouping.

Dividend

The number being divided in a division problem. In 56 / 8 = 7, the number 56 is the dividend.

Divisor

The number you divide by. In 56 / 8 = 7, the number 8 is the divisor.

Order of operations

A set of rules for the order in which to do calculations: parentheses first, then exponents, then multiplication and division, then addition and subtraction.

Parentheses

The symbols ( ) used to group parts of an expression and show what to calculate first.

Product

The result of multiplying two or more numbers together. The product of 6 and 7 is 42.

Quotient

The result of dividing one number by another. When you divide 45 by 9, the quotient is 5.

Remainder

The amount left over when a number does not divide evenly. 17 / 5 = 3 remainder 2.

place-value

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