An angle with a measure less than 90°.

To combine, put together two or more quantities.

A step-by-step method for computing.

Two rays that share an endpoint.

The measure of the size of an angle. It tells how far one side is turned from the other side. A one degree angle turns through 1/360 of a full circle.

The measure, in square units, of the inside of a plane figure.

A model of multiplication that shows each place value product.

An arrangement of objects in equal rows.

Changing the grouping of three or more addends does not change the sum.

Changing the grouping of three or more factors does not change the product.

A characteristic of an object, such as color, shape, size, etc.

Capacity refers to the amount of liquid a container can hold.

A metric unit of length equal to 0.01 of a meter.

A plane figure with all points the same distance from a fixed point called a center.

To sort into categories or to arrange into groups by attributes.

Changing the order of the addends does not change the sum.

Changing the order of the factors does not change the product.

To decide if one number is greater than, less than, or equal to.

To put together components or basic elements.

A number greater than 0 that has more than two different factors.

Having exactly the same size and shape.

A collection of information gathered for a purpose. Data may be in the form of either words or numbers.

A number with one or more digits to the right of a decimal point.

A fractional number with a denominator of 10 or a power of 10. Usually written with a decimal point.

A dot (.) separating the whole number from the fraction in decimal notation.

To separate into components or basic elements.

A unit for measuring angles. Based on dividing one complete circle into 360 equal parts.

The quantity below the line in a fraction. It tells how many equal parts are in the whole.

Any of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

The amount that remains after one quantity is subtracted from another.

When one of the factors of a product is a sum, multiplying each addend before adding does not change the product.

To separate into equal groups and find the number in each group or the number of groups.

A number that is divided by another number.

The number by which another number is divided.

A point at either end of a line segment, or a point at one end of a ray.

Having the same value.

A mathematical sentence with an equals sign. The amount on one side of the equals sign has the same value as the amount on the other side.

Fractions that have the same value.

To find a number close to an exact amount; an estimate tells about how much or about how many.

To find the value of a mathematical expression.

A way to write numbers that shows the place value of each digit.

A mathematical phrase without an equal sign.

The whole numbers that are multiplied to get a product.

A set of two whole numbers when multiplied, will result in a given product.

A rule that is written as an equation.

A way to describe a part of a whole or a part of a group by using equal parts.

A table that lists pairs of numbers that follow a rule.

The standard unit of mass in the metric system. 1,000 grams = 1 kilogram

Greater than is used to compare two numbers when the first number is larger than the second number.

One of the equal parts when a whole is divided into 100 equal parts.

In the decimal numeration system, hundredths is the name of the next place to the right of tenths.

A term for a fraction whose numerator is greater than or equal to its denominator.

Lines that cross at a point.

Operations that undo each other.

A metric unit of mass equal to 1000 grams.

A metric unit of length equal to 1000 meters.

Less than is used to compare two numbers when the first number is smaller than the second number.

Denominators in two or more fractions that are the same.

A set of connected points continuing without end in both directions.

A line that divides a figure into two congruent halves that are mirror images of each other.

A diagram showing frequency of data on a number line.

A part of a line with two endpoints.

The amount of matter in an object. Usually measured by comparing with an object of known mass. While gravity influences weight, it does not affect mass.

A standard unit of length in the metric system.

A system of measurement based on tens. The basic unit of capacity is the liter. The basic unit of length is the meter. The basic unit of mass is the gram.

A metric unit of length. 1,000 millimeters = 1 meter

One sixtieth of an hour or 60 seconds.

A number that has a whole number (not 0) and a fraction.

A product of a given whole number and any other whole number.

The operation of repeated addition of the same number.

A diagram that represents numbers as points on a line.

The number written above the line in a fraction. It tells how many equal parts are described in the fraction.

An angle with a measure greater than 90º but less than 180º.

A customary unit of weight equal to one sixteenth of a pound. 16 ounces = 1 pound.

Lines that are always the same distance apart. They do not intersect.

Used in mathematics as grouping symbols for operations. When simplifying an expression, the operations within the parentheses are performed first.

A repeating or growing sequence or design. An ordered set of numbers or shapes arranged according to a rule.

The distance around the outside of a figure.

In a large number, periods are groups of 3 digits separated by commas or by spaces.

Two intersecting lines that form right angles.

The value of the place of a digit in a number.

A two-dimensional figure.

The exact location in space represented by a dot.

A whole number greater than 0 that has exactly two different factors, 1 and itself.

The answer to a multiplication problem.

A tool used to measure and draw angles.

The answer to a division problem.

A part of a line that has one endpoint and goes on forever in one direction.

An answer that is based on good number sense.

The amount left over when one number is divided by another.

An angle that measures exactly 90º.

A triangle that has one 90º angle.

To find the nearest ten, hundred, thousand, (and so on).

One sixtieth of a minute. There are 60 seconds in a minute.

When a fraction is expressed with the fewest possible pieces, it is in simplest form. (Also called lowest terms.)

To express a fraction in simplest form.

A unit, such as square centimeter or square inch, used to measure area.

A common or usual way of writing a number using digits.

An operation that gives the difference between two numbers. Subtraction can be used to compare two numbers, or to find out how much is left after some is taken away.

The answer to an addition problem.

One of the equal parts when a whole is divided into 10 equal parts.

Having length and width. Having area, but not volume. Also called a plane figure.

A fraction that has 1 as its numerator.

Denominators that are not equal.

A letter or symbol that represents a number.

The point at which two line segments, lines, or rays meet to form an angle.

The number of cubic units it takes to fill a figure.

Whole numbers are zero and the counting numbers 1, 2, 3, 4, 5, 6, and so on. If a number has a negative sign, a decimal point, or a part that's a fraction, it is not a whole number.

A way of using words to write a number.