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Math

8th grade (U.S.)

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
A thumbnail for: Numbers and operations
33 15

Numbers and operations
A thumbnail for: Solving equations
17 5

Solving equations
A thumbnail for: Relationships and functions
56 20

Relationships and functions
A thumbnail for: Systems of equations
42 15

Systems of equations
A thumbnail for: Geometry
31 13

Geometry
A thumbnail for: Data and modeling
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Data and modeling
Solving equations

Linear equations in one variable

You started first solving equations in sixth and seventh grade. You'll now extend this skill by tackling fancier equations that have variables on both sides. Common Core Standards: 8.EE.C.7, 8.EE.C.7b

Solving equations with distribution

In this tutorial, we'll look at slightly more complicated equations that just having variables on both sides. If you can solve these, you're well on your way to mastering equations! Common Core Standards: 8.EE.C.7, 8.EE.C.7b

Solutions to linear equations

No all equations in one variable have exactly one solution. Some have no solutions and some are true for any value of the unknown. In this tutorial, we'll learn to tell the difference (and understand why this is). Common Core Standard: 8.EE.C.7a

Linear equation word problems

In 72 years, Sal will be 3 times as old as he is today (although he might not be... um... capable of doing much). How old is Sal today? The sum of 5 consecutive integers is 15; what are the integers? These classic questions have plagued philosophers through the ages. Actually, they haven't. But they have plagued algebra students! Even though few people ask questions like this in the real-world, these are strangely enjoyable problems.