8th grade is all about tackling the meat of algebra and getting exposure to some of the foundational concepts in geometry. If you get this stuff (and you should because you're incredibly persistent), the rest of your life will be easy. Okay, maybe not your whole life (no way to avoid the miseries of wedding planning), but at least your mathematical life. Seriously, we're not kidding. If you get the equations and functions and systems that we cover here, most of high school will feel intuitive (even relaxing). If you don't, well.. at least you have high school to catch up. :) On top of that, we will sharpen many of the skills that you last saw in 6th and 7th grades. This includes extending our knowledge of exponents to negative exponents and exponent properties and our knowledge of the number system to irrational numbers! (Content was selected for this grade level based on a typical curriculum in the United States.)
Community Questions

# Numbers and operations

All content in “Numbers and operations”

## Repeating decimals

Some fractions are hard to write as decimals. For example, 1/3 = 0.3333333... The decimal repeats! In this tutorial, we learn how to convert between repeating decimals and fractions.

## Square roots and cube roots

A strong contender for coolest symbol in mathematics is the radical. What is it? How does it relate to exponents? How is the square root different than the cube root? Common Core Standards: 8.EE.A.2

## Negative exponents

It's normally a bad idea to hang around with negative people or do negative things, but we think it's OK to associate with negative exponents. Common Core Standards: 8.EE.A.1

## Exponent properties

Tired of hairy exponent expressions? Feel compelled to clean them up? Well, this tutorial might just give you the tools you need. If you know a bit about exponents, you'll learn a ton more in this tutorial as you learn about the rules for simplifying exponents. Common Core Standards: 8.EE.A.1

## Orders of magnitude

When people want to think about the general size of things but not worry about the exact number, they tend to think in terms of "orders of magnitude". This allows us to analyze and make comparisons between numbers very quickly, which allows us to make decisions about them quickly as well. Common Core Standard: 8.EE.A.3

## Scientific notation intro

Scientists and engineers often have to deal with super huge (like 6,000,000,000,000,000,000,000) and super small numbers (like 0.0000000000532) . How can they do this without tiring their hands out? How can they look at a number and understand how large or small it is without counting the digits? The answer is to use scientific notation. If you come to this tutorial with a basic understanding of positive and negative exponents, it should leave you with a new appreciation for representing really huge and really small numbers! Common Core Standard: 8.EE.A.4

## Arithmetic with numbers in scientific notation

You already understand what scientific notation is. Now you'll actually use it to compute values and solve real-world problems. Common Core Standard: 8.EE.A.4