addend - One of two or more numbers that are added together. In 2 + 3 + 4, the addends are 2,3,and 4.
area - The measure of a bounded surface, like the top of a table, or the floor of a room. Area is measured in square units.
average - The result of dividing the sum two or more quantities by the number of quantities. It is also called the mean.
base ten - The system of numeration we use in which the value of each "place" is 10 times the value of the place to its right. It is also called the decimal numeration system, or standard notation.
Celsius - The temperature scale on which pure water at sea level freezes at 0° and boils at 100°. The Celsius scale is used in the metric system.
data - Information that is gathered by observing, counting or measuring.
diagonal - 1)A line of objects or numbers from the upper left to the lower right, or from the lower left to the upper right. 2) A line segment joint two non-adjacent vertices of a polygon.
difference - The amount by which one number is great or less than another number; the result of subtracting one number from another. It is the answer to a subtraction problem.
digit - In the base-ten numeration system, one of the symbols 0,1,2,3,4,5,6,7,8,9, which can be used to write any number.
divisible - One whole number is divisible by another whole number is there is no remainder when the larger number is divided by the smaller number.
estimate - a close, rather than exact, answer; an approximate answer to a computation
even number - A whole number that can be evenly divided by 2.
fact family - A collection of related addition and subtraction facts, or multiplication and division facts, made from the same numbers. For 7, 8, and 15, the addition/subtraction fact family consists of 7 + 8 = 15, 8 + 7 = 15, 15 - 8 = 7, 15 - 7 = 8. For 9, 6, and 54, the multiplication/division fact family consists of 6 * 9 = 54, 9 * 6 = 54, 54/9 = 6, 54/6 = 9.
factor - 1)A number being multiplied in a multiplication number model. 2) A whole number that can divide another whole number without a remainder.
Fahrenheit - The temperature scale on which pure water at sea level freezes at 32° and boils at 212°.
horizontal - Positioned in a left-to-right orientation. Parallel to the horizon.
mean - The result of dividing the sum two or more quantities by the number of quantities. It is often called the average.
median - The middle value of a set of data when the data are listed in order from least to greatest or greatest to least. It is also known as the middle value.
metric system - A measurement system based on the base-ten numeration system and used in most countries around the world.
mile - one mile equals 5,280 feet or 1.609344 kilometers.
mode - The value or values that occur most often in a set of data.
multiples - Repeated groups of the same amount. Multiples of a number of the product of that number and another number.
negative number - A number less than 0; a number to the left of zero on a horizontal number line, or a number below 0 on a vertical number line or thermometer.
number model - A number sentence that models or fits the situation. An equation.
odd number - A whole number that cannot be evenly divided by 2.
ordinal number - A number used to express position or order in a series, such as 1st, 2nd, 3rd.
parallel - Lines, rays, line segments, and planes that are equidistant at all points, no matter how far they extend.
prime number - A whole number greater than 1 that has exactly two whole number factors, 1 and itself. The first five prime numbers are 2,3,5,7, and 11.
product - The result of a multiplication problem. The product of 3 x 5 is 15. It is the answer to a multiplication problem.
quotient - The result of dividing one number by another number. The answer to a division problem.
remainder - An amount left over when one number is divided by another number.
right angle - a perpendicular angle, always measuring 90°.
sum - The result of adding two or more numbers. The answer to an addition problem.
units of capacity -
vertical - Upright; perpendicular to the horizon.
volume - A measure of the amount of space occupied by a 3-dimensional shape. Usually expressed in "cubic" units. To learn how to calculate the volume of a box, click here.
weight - A measure of how heavy something is.
Glossary terms were based on the glossary in Everyday Mathematics: Teacher's Reference Manual, Grades 4-6, University of Chicago, 2002.