# 8th Grade Math Vocabulary Words

## 8th Grade Math Words

8th grade is a very important time. It's that last year before you enter high school and four years of a more rigorous and challenging curriculum. By the time you get to high school, you want to make sure you know as many important math related words as possible. Why? Look at it this way. if you don't know the words of the English language, you can't read, write, or talk. The same is true for math. If you don't know the words of math, you won't be able to read, write, or speak math. It's kind of hard to do well in school if you aren't prepared.

There are a lot of math words you should know by the end of 8th grade. This lesson can't possibly cover all of them, but you will learn some of the more commonly used math terms.

## Math Words A-M

Let's start with **absolute value**. This refers to the distance a number is from zero. The absolute value of any number is always positive. The absolute value is written as |x|, where x is a number. For example, the absolute value of 200, |200|, is 200. The absolute value of -200, |-200|, is also 200.

That wasn't too hard and neither is the next term, **acute angle**. Think of it as being a tiny cute angle. Since it's tiny it has to be less than 90 degrees. Thus, an acute angle is one that is greater than 0 degrees but less than 90 degrees.

Angles are sometimes drawn on a coordinate plane. You know, that's the one with the horizontal and vertical axis that intersect at a right angle. In a coordinate plane, an axis is the x or the y line that cross one another at a right angle. In a coordinate plane, each point has a **coordinate**,a number, denoted as (x,y), that shows the point's position.

We can use these coordinates to help rotate figures on a coordinate plane clockwise or counterclockwise. Remember, a **clockwise** direction refers to the same direction the hands of a clock move while **counterclockwise** means a movement in the opposite direction.

Shapes don't exist solely on paper, of course. We have three-dimensional shapes, like cubes. But in math, cube refers to more than just a shape. **Cube** can be taken to mean the third power of some number. For example, if we were to cube 2, the answer would be 8, from 2 x 2 x 2.

You should also know simple terms related to triangles. For example, the **hypotenuse** is the longest side of a right triangle. The other two sides are called legs. A right triangle is a triangle that has a right angle. In other words, it has a 90-degree angle. The legs are the two sides of a right triangle that actually form this 90-degree angle while the hypotenuse is the side opposite the right angle.

## Math Words N-Z

But not all triangles have right angles. Some have an **obtuse angle**, an angle that is greater than 90 degrees but less than 180 degrees.

Enough with the triangles though, let's move on to something else. Do you know what perpendicular and parallel lines are? If not, here is a quick review. **Perpendicular lines** are lines that intersect in such a way that they form a right angle. On the other hand, **parallel lines** are lines running in such a way that they that never intersect one another.

**Rate** is another important math word. A rate refers to a division comparison or relation between two different units of measure. For instance, you've probably heard someone saying they were going 60 mph. Mph, which stands for miles per hour and is written mathematically as miles/hour is a rate. So is liters/sec (read as liters per second) and other such examples.

Have you studied reciprocals yet? You will need to understand this term too for your high school math classes. A **reciprocal** is a multiplicative inverse. That may be giving you a headache but it's really easy! The reciprocal of x (which can be seen as x/1) is 1/x. The reciprocal of 2/3 is 3/2. Not so hard now, is it?

Last, but not least, is the term **variable**. The variable is some sort of letter (like x) or symbol (such as sigma) that represents an unknown quantity. For instance, in 1x + 5 the variable is x. In 3y + 7, the variable is y.

## Lesson Summary

These math words are the basic, yet essential, concepts you should know by the end of 8th grade. Take this list of math vocabulary with you to your math classes and use it to complete your homework. By the end of your 8th-grade year, you'll know these concepts without having to use a glossary.

- The
**absolute value**refers to the distance a number is from zero. - An
**acute angle**is one that is greater than 0 degrees but less than 90 degrees. - A
**coordinate**, denoted as (x,y), shows a point's position on the coordinate plane. - The
**clockwise**direction refers to the same direction the hands of a clock move while**counterclockwise**means a movement in the opposite direction. - A
**cube**is the third power of some number. - The
**hypotenuse**is the longest side of a right triangle. - An
**obtuse angle**is greater than 90 degrees but less than 180 degrees. **Perpendicular lines**are lines that intersect in such a way that they form a right angle while**parallel lines**are lines running in such a way that they that never intersect one another.- A
**rate**refers to a division relation between two different units of measure. - A
**reciprocal**is a multiplicative inverse. - A
**variable**is some sort of letter (like x) or symbol (such as sigma) that represent an unknown quantity.

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Back*8th Grade Math Vocabulary Words*

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