ALL 5th Grade Vocabulary

Vocabulary practice flashcards generated from Grade 5 Math Content Summary covering fractions, decimals, prime factorization, operations properties, metric units, geometry, measures of center, probability, and algebra.

Proper Fraction

A fraction where the numerator is less than the denominator (e.g., $\frac{1}{2}$, $\frac{7}{8}$).

Improper Fraction

A fraction where the numerator is equal to or greater than the denominator (e.g., $\frac{12}{7}$, $\frac{4}{4}$), which can also be expressed as a mixed number.

Repeating Decimal

A decimal in which a digit or pattern of digits repeats endlessly, represented with a line over the repeating digit or an ellipsis (e.g., $0.\bar{6}$ or $0.666\dots$).

Prime Number

A whole number greater than 1 that has exactly two distinct factors: 1 and the number itself.

Composite Number

A whole number greater than 1 that has more than two different factors.

Prime Factorization

A representation of a composite number expressed as the product of its prime factors.

Commutative Property of Addition

The property stating that changing the order of addends does not change the sum ($a + b = b + a$).

Commutative Property of Multiplication

The property stating that changing the order of factors does not change the product ($a \cdot b = b \cdot a$).

Associative Property of Addition

The property stating that changing the grouping of addends does not change the sum ($(a + b) + c = a + (b + c)$).

Associative Property of Multiplication

The property stating that changing the grouping of factors does not change the product ($(ab)c = a(bc)$).

Distributive Property

The property stating that multiplying a sum or difference by a number gives the same result as multiplying each term individually and adding or subtracting ($a(b + c) = ab + ac$ and $a(b - c) = ab - ac$).

Simplest Form

The form of a fraction where the numerator and denominator are divided by their greatest common factor until they share no common factors other than 1.

Dividend, Divisor, and Quotient

The structural parts of a division expression, where $\text{dividend} \div \text{divisor} = \text{quotient}$.

Order of Operations (PEMDAS)

The standard mathematical rule for evaluating expressions: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right).

Mass

The measure of the amount of matter in an object, typically measured in grams or kilograms using a balance.

Weight

The measure that accounts for the force of gravity acting on an object's mass.

Metric Length Units

Units used to measure length, including kilometer ($1000\,\text{m}$), meter ($100\,\text{cm}$ or $1000\,\text{mm}$), centimeter ($10\,\text{mm}$), and millimeter.

Perimeter

The total distance around a two-dimensional (plane) figure, calculated for a rectangle as $2 \times \text{length} + 2 \times \text{width}$.

Area

The number of square units required to cover a surface or two-dimensional figure ($\text{length} \times \text{width}$ for a rectangle; $\frac{1}{2} \times \text{base} \times \text{height}$ for a right triangle).

Volume

The measure of space occupied by a three-dimensional figure, calculated for a rectangular prism as $\text{length} \times \text{width} \times \text{height}$ and expressed in cubic units.

Right Angle

An angle that measures exactly $90^\circ$.

Acute Angle

An angle that measures between $0^\circ$ and $90^\circ$.

Obtuse Angle

An angle that measures between $90^\circ$ and $180^\circ$.

Straight Angle

An angle that measures exactly $180^\circ$.

Classification of Angles

The categorization of angles based on measure: acute (under $90^\circ$), right (exactly $90^\circ$), obtuse (over $90^\circ$), and straight ($180^\circ$).

Scalene Triangle

A triangle in which all three sides have different lengths (no congruent sides).

Isosceles Triangle

A triangle that has at least two congruent sides.

Equilateral Triangle

A triangle with three congruent sides and three congruent angles, each measuring $60^\circ$.

Types of Triangles

Triangles classified either by their side lengths (equilateral, isosceles, scalene) or by their angle measures (acute, right, obtuse).

Line Plot

A graph that shows data frequency along a number line using symbols such as X.

Stem-and-Leaf Plot

A data display that organizes numbers by separating each value into a stem (leading digit) and a leaf (trailing digit).

Mean

A measure of center representing 'fair share,' found by calculating the sum of all data points and dividing by the total number of data points.

Median

The middle value in an ordered set of data points, or the mean of the two middle values if the set has an even number of data points.

Mode

The value or values that appear most frequently in a data set.

Range

A measure of spread calculated as the difference between the greatest and smallest values in a data set.

Probability

The measure of likelihood that an event will occur, expressed as a fraction between 0 (impossible) and 1 (certain): $\frac{\text{number of favorable outcomes}}{\text{total number of possible outcomes}}$.

Fundamental Counting Principle

A rule used to find the total number of possible outcomes by multiplying the number of choices available for each category.

Input-Output Table

A table showing a functional pattern where a specific mathematical rule is applied to input values to generate output values.

Variable

A symbol or letter used to represent an unknown numerical value in an expression or equation.

Expression

A mathematical phrase consisting of numbers, variables, and operation symbols that represents a quantity without an equal sign (e.g., $x + 3$).

Equation

A mathematical statement showing that two expressions are equal, containing numbers, variables, and an equal sign (e.g., $y + 7 = 10$).