3rd Grade Mathematics Vocabulary Flashcards

Vocabulary practice flashcards covering place value, operations, fractions, geometry, measurement, and data based on the 3rd Grade Math curriculum.

Standard Form

A way to write a number using digits (for example, $492$).

Word Form

A way to write a number using words (for example, Four hundred ninety-two).

Expanded Form

A way to write a number that shows the value of each digit (for example, $400 + 90 + 2$ or $(4 \times 100) + (9 \times 10) + (2 \times 1)$).

Digit

A single symbol used to represent a number (for example, in the number $475$, the digits are $4$, $7$, and $5$).

Place Value

The value of a digit based on its position in a number, such as hundreds, tens, and ones.

Expression

A mathematical phrase that has at least $2$ numbers and at least one math operation symbol (such as addition, subtraction, multiplication, or division).

Equation

A mathematical statement containing an equal sign ($=$) showing that what is on one side is equal to what is on the other side.

Compose

To put numbers or geometric shapes together from smaller parts.

Decompose

To separate a number or geometric shape into parts or break it apart (for example, $43 = 4\text{ tens} + 3\text{ ones}$).

Estimate

A thoughtful guess about a number or mathematical answer.

Sum

The result or answer obtained when adding two or more numbers together.

Difference

The result or answer obtained when subtracting one number from another.

Product

The result or answer obtained by multiplying whole numbers together.

Factor

One of two or more whole numbers multiplied together to get a product.

Array

An arrangement of objects in equal rows and columns.

Division

The operation of finding the number of equal groups or finding the size of each equal group when sharing a total amount.

Quotient

The result or answer in a division problem.

Divisor

The number by which another number is divided, representing either the number of groups or the size of each equal group.

Dividend

The total number or amount being divided into equal groups.

Polygon

A two-dimensional, closed plane shape made of straight line segments that do not cross.

Triangle

A polygon with exactly $3$ sides and $3$ angles.

Quadrilateral

A polygon with exactly $4$ sides and $4$ angles.

Pentagon

A polygon with exactly $5$ sides and $5$ angles.

Hexagon

A polygon with exactly $6$ sides and $6$ angles.

Octagon

A polygon with exactly $8$ sides and $8$ angles.

Regular Polygon

A polygon in which all sides are equal in length and all angles are equal in size.

Irregular Polygon

A polygon in which the sides and angles are not all equal in size.

Subdivide

Separating one polygon into two or more smaller polygons.

Combine

Putting two or more polygons together to form a single larger polygon.

Fraction

A number used to describe parts of a whole or set that has been partitioned into equal parts.

Numerator

The top number of a fraction that tells how many equal parts are being counted or described.

Denominator

The bottom number of a fraction that tells the total number of equal parts in the whole.

Unit Fraction

A fraction that has a numerator of $1$.

Proper Fraction

A fraction less than $1$ in which the numerator is smaller than the denominator.

Improper Fraction

A fraction greater than or equal to $1$ in which the numerator is equal to or greater than the denominator.

Mixed Number

A number expressed as a whole number combined with a fraction less than $1$.

Scaled Pictograph

A picture graph where each symbol or picture represents an amount other than $1$.

Key

A part of a graph that explains what each symbol or picture represents.

Algorithm

A step-by-step set of rules or instructions used to solve a mathematical problem.

Parentheses

Grouping symbols $( \quad )$ used in expressions or equations to show which operations to compute first.

Equivalent

Having the same value or amount, even if expressed or represented in a different form.

Data

A collection of facts, numbers, or information.

Pattern

A set of numbers, letters, shapes, or pictures that repeat or grow according to a specific rule.

Perimeter

The measure of the total length around the outside of a plane shape.

Area

The measure of the space inside a two-dimensional shape, measured in square units.

Elapsed Time

The amount of time that passes between two given times.

Penny

A coin worth $1\text{ cent}$ ($\$0.01$).

Nickel

A coin worth $5\text{ cents}$ ($\$0.05$).

Dime

A coin worth $10\text{ cents}$ ($\$0.10$).

Quarter

A coin worth $25\text{ cents}$ ($\$0.25$).

Dollar

A unit of money equal to $100\text{ cents}$ ($\$1.00$).