N I O I P I Q I R I S I T I U I V I W I X I Y I Z

**A**I B I C I D I E I F I G I H I I I J I K I L I MN I O I P I Q I R I S I T I U I V I W I X I Y I Z

## E

The line segment where two faces of a polyhedron meet.

To remove, to get rid of.

The set of all points in a plane such that the sum of the distances to two fixed points is a constant.

On a ray, segment, arc, or vector, a point at which the curve begins or ends; a point which touches only one other point on the curve.

To be the same in value (=).

A mathematical statement that says two expressions have the same value; any number sentence with an =.

The same distance.

A figure containing all equal sides.

A triangle that has three equal sides.

Two or more expressions that have the same value.

Two equations with the same solutions.

Fractions that reduce to the same number.

The difference between an approximate measurement and the actual measure taken.

An approximate calculation of a value.

To substitute number values into an expression.

A natural number that is evenly divisible by 2.

In probability, a set of outcomes.

Method of writing numbers as the sum of powers of ten or as the sum of its units, tens, hundreds, etc. (53,245 = 50,000 + 3,000 + 200 + 40 + 5)

A number that indicates the operation of repeated multiplication.

A mathematical symbol, or combination of symbols, representing a value, or relation. Example: 2+2=4

The angle outside a polygon formed by extending one of its sides.

**edge**The line segment where two faces of a polyhedron meet.

**eliminate**To remove, to get rid of.

**ellipse**The set of all points in a plane such that the sum of the distances to two fixed points is a constant.

**endpoint**On a ray, segment, arc, or vector, a point at which the curve begins or ends; a point which touches only one other point on the curve.

**equals**To be the same in value (=).

**equation**A mathematical statement that says two expressions have the same value; any number sentence with an =.

**equidistant**The same distance.

**equilateral**A figure containing all equal sides.

**equilateral triangle**A triangle that has three equal sides.

**equivalent**Two or more expressions that have the same value.

**equivalent equations**Two equations with the same solutions.

**equivalent fractions**Fractions that reduce to the same number.

**error of measurement**The difference between an approximate measurement and the actual measure taken.

**estimate**An approximate calculation of a value.

**evaluate**To substitute number values into an expression.

**even number**A natural number that is evenly divisible by 2.

**event**In probability, a set of outcomes.

**expanded notation**Method of writing numbers as the sum of powers of ten or as the sum of its units, tens, hundreds, etc. (53,245 = 50,000 + 3,000 + 200 + 40 + 5)

**exponent**A number that indicates the operation of repeated multiplication.

**expression**A mathematical symbol, or combination of symbols, representing a value, or relation. Example: 2+2=4

**exterior angle of a polygon**The angle outside a polygon formed by extending one of its sides.