A.M.: The time between midnight and noon
absolute value: The distance of a number from zero on a number line
Example:
|-4|The absolute value of -4 is 4.
|+4|The absolute value of +4 is 4.
acute angle: An angle that has a measure less than a right angle (less than 90°)
Example:
addend: A number that is added to another in an addition problem
Example: 2 + 3 = 5
The addends are 2 and 3.
addition: The process of finding the total number of items when two or more groups of items are joined; the opposite operation of subtraction
analog clock: A device for measuring time by moving hands around a circle for showing hours, minutes, and sometimes seconds
angle: A figure formed by two line segments or rays that share the same endpoint
Example:
area: The number of square units needed to cover a surface
Example:
The area is 9 square units.
array: An arrangement of objects in rows and columns
ascending: From least to greatest number
Example: These numbers are in ascending order.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Associative Property of Addition: The property stating that you can group addends in different ways and still get the same sum (Grouping Property)
Example:
(5 + 9) + 3 = 5 + (9 + 3)
14 + 3 = 5 + 12
17 = 17
Associative Property of Multiplication: The property stating that you can group factors in different ways and still get the same product (Grouping Property)
Example:
(2 x 3) x 4 = 2 x (3 x 4)
6 x 4 = 2 x 12
24 = 24
average: The number found by dividing the sum of a set of numbers by the numbers of addends (Mean)
axis: The horizontal or vertical number line used in a coordinate plane; the line at the side or bottom of a graph
Example:
bar graph: A graph that uses bars to show data
Example:
base: A side of a polygon or a face of a solid figure by which the figure is measured or named
Examples:
base: A number used as a repeated factor
Example: 83= 8 x 8 x 8.
The base is 8.
Example: Use the benchmark to decide which is the most reasonable number of beans in the jar.
100 400 4,000
Benchmark: 50 beans /
A reasonable number of beans in the jar is 400.
billion: One thousand million
calendar: A table that shows the days, weeks, and months of a year
capacity: The amount a container can hold when filled
cardinal number: A number that tells how many items are in a group.
Examples: 4 puppies, 93 cents
center: The point inside a circle that is the same distance from each point on the circle
Example:
central angle: The angle formed by two radii of a circle that meet at its center
Example:
centimeter (cm): A metric unit for measuring length
Examples:
100 centimeters = 1 meter
A centimeter (cm) is about the width of your index finger.
century: A measure of time on a calendar, equal to one hundred years
certain: An event is certain if it will always happen
chord: A line segment with endpoints on a circle
Example:
circle: A closed plane figure made up of points that are the same distance from the center
circle graph: A graph in the shape of a circle that shows data as a whole made up of different parts
Example:
circumference: The distance around a circle
closed figure: A figure that begins and ends at the same point
Examples:
common factor: A number that is a factor of two or more numbers
Example:
factors of 12: / 1, 2, 3, 4, 6, 12
The common factors of 6 and 12 are 1, 2, 3, and 6.
common multiple: A number that is a multiple of two or more numbers
Example:
multiples of 6: / 6, 12, 18, 24, 30
A common multiple of 4 and 6 is 24.
Commutative Property of Addition: The property that states that when the order of two or more addends is changed, the sum is the same
Example: 4 + 5 = 5 + 4
Commutative Property of Multiplication: The property that states that when the order of two or more factors is changed, the product is the same
Example: 5 x 7 = 7 x 5
compass: A tool used to draw circles
compatible numbers: Nearby numbers that are easy to compute mentally
Example:
Estimate. 528 ÷ 7
490 ÷ 7 = 7049 and 7 are compatible.
560 ÷ 7 = 8056 and 7 are compatible.
composite number: A whole number that has more than two factors
Example:9 is a composite number since its factors are 1, 3, and 9.
cone: A solid, pointed figure that has a flat, round base
Example:
congruent: Having the same size and shape
Example:
The triangles are congruent.
coordinate grid: A grid formed by a horizontal line, called an x-axis, and a vertical line, called a y-axis
Example:
corner: The point at which two rays of an angle or two or more line segments meet in a plane figure, or where three or more sides meet in a solid figure (Vertex) Examples:
cube: A solid figure with six congruent square faces
Examples:
cubic unit: A unit of volume with dimensions of one unit times one unit times one unit
Example: 4 cubic units
cup (c): A customary unit used to measure capacity
Example:
8 ounces = 1 cup
cylinder: A solid figure that is shaped like a can
Example:
data: Information collected about people or things
decade: A measure of time equal to 10 years
decimal: A number with one or more digits to the right of the decimal point
Example: 3.47
decimal number system: A place value number system based on grouping by tens; each place has a value 10 times the value of the place at its right
Example:
decimal point: A symbol used to separate dollars from cents in money and to separate the ones place from the tenths place in decimals
Example:
decimeter: A metric unit for measuring length
Examples:
10 centimeters = 1 decimeter
A decimeter (dm) is about the width of an adult's hand.
degree: A unit used for measuring angles or temperatures
Examples:
denominator: The number below the bar in a fraction. It tells how many equal parts are in the whole.
Example:
descending: From greatest to least number
Example: These numbers are in descending order.
10, 9, 8, 7, 6, 5, 4, 3, 2, 1
diameter: A line segment that passes through the center of a circle and has its endpoints on the circle.
Example:
diameter
difference: The answer in a subtraction problem
Example:
8 - 5 = 3
3 is the difference.
digit: Any one of the ten symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 used to write numbers
digital clock: A clock that shows time to the minute using digits
dimension: A measure in one direction
Distributive Property of Multiplication: The property that states that multiplying a sum by a number is the same as multiplying each addend by the number and then adding the products
Example:
3 x 6 / = 12 + 6
18 / = 18
dividend: The number that is to be divided in a division problem
Example: 3 5 ÷ 5 = 7 The dividend is 35
divisible: Capable of being divided so that the quotient is a whole number and the remainder is zero.
Example: 21 is divisible by 3.
division: The process of sharing a number of items to find how many groups can be made or how many items will be in each group; the opposite operation of multiplication
divisor: The number that divides the dividend
Example: 18 ÷ 3 = 6
The divisor is 3
double-bar graph: A bar graph used to compare similar kinds of data
Example:
edge: The line segment where two
faces of a solid figure meet
Example:
edge
elapsed time: The amount of time that passes from the start of an activity to the end of that activity
equally likely: Having the same chance of happening
Example: You are equally likely to roll 1, 2, 3, 4, 5, or 6 on a die.
equation: A number sentence which shows that two quantities are equal
Examples:
9 - 3 = 6
n + 7 = 15
equilateral triangle: A triangle with three congruent sides
Example:
equivalent: Having the same value or naming the same amount
equivalent decimals: Two or more decimals that name the same amount
Example:
0.3 and 0.30 name the same amount.
So, 0.3 and 0.30 are equivalent.
0.3 = 0.30
equivalent fractions: Two or more fractions that name the same amount
Example:
estimate (noun): A number close to an exact amount
estimate (verb): To find a number that is close to an exact amount
Example:
x
30 x 10 = 300 estimate
32 x 9 is about 300
evaluate: To find the value of a numerical or algebraic expression
Example:
event: One outcome or a combination of outcomes in an experiment
expanded form: A way to write numbers by showing the value of each digit
Examples:
635 = 600 + 30 + 5
1,479 = 1,000 + 400 + 70 + 9
exponent: A number that shows how many times the base is used as a factor
Example:
The exponent is 3, indicating that 8 is used as a factor 3 times.
expression: A part of a number sentence that combines numbers and operation signs but does not have an equal sign
Example: (12 - 4) - 3
face: A polygon that is a flat surface of a solid figure
Example:
fact family: A set of related multiplication and division,
or addition and subtraction, equations
Examples:
2 + 4 = 6 6 - 4 = 2
4 + 2 = 6 6 - 2 = 4
3 x 6 = 18 18 ÷ 6 = 3
6 x 3 = 18 18 ÷ 3 = 6
factor: A number that is multiplied by another number to find a product
Examples:
4 x 7 = 28 / x 7
28
The factors are 4 and 7
factor tree: A diagram that shows the prime factors of a number
Example:
fairness: Fairness in a game means that one player is as likely to win as another. Each player has an equal chance of winning.
foot (ft): A customary unit for measuring length or distance
Examples: 12 inches = 1 foot
A foot (ft) is about the length of a sheet of paper.
formula: A set of symbols that expresses a mathematical rule
Example: formula for area of a rectangle:
Area = length x width or A = l x w
fraction: A number that names part of
a whole or part of a group
Example:
frequency: The number of times an event occurs
frequency table: A table that uses numbers to record data about how often something happens
Example:
Day / Number of Students
(Frequency)
Monday / 15
Tuesday / 13
Wednesday / 5
Thursday / 9
Friday / 17
function: A relationship between two quantities in which one quantity depends on the other
function table: A table that matches each input value with an output value. The output values are determined by the function.
Example:
Multiply
by 3. / Output
2 / 6
Input / x / 2 / 4 / 5
Output / y / 6 / 12 / 15
gallon (gal): A customary unit for measuring capacity
Example: 4 quarts = 1 gallon
gram (g): A metric unit for measuring mass
Examples: 1,000 grams = 1 kilogram
greater than (>):A symbol used to compare two numbers, with the greater number given first
Example: 8 > 6
8 is greater than 6
greatest common factor: The greatest factor that two or more numbers have in common
Example:
18: 1, 2, 3, 6, 9, 18
30: 1, 2, 3, 5, 6, 10, 15, 30
6 is the GCF of 18 and 30
grid: Evenly divided and equally spaced squares on a figure or flat surface
Example:
height: The length of a perpendicular from the base to the top of a plane figure or solid figure
Example:
hexagon: A polygon with six sides and six angles
Examples:
hour hand (hr): The short hand on an analog clock
horizontal: The direction from left to right
Example:
horizontal
hundredth: One of one hundred equal parts
Example:
hypotenuse: In a right triangle, the side opposite the right angle; the longest side in a right triangle
Example:
impossible: Never able to happen
inch (in.): A customary unit for measuring length
Examples: 12 inches = 1 foot
An inch (in.) is about the length of your thumb from the first knuckle to the tip.