If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

7th grade (U.S.)

7th grade takes much of what you learned in 6th grade to an entirely new level. In particular, you'll now learn to do everything with negative numbers (we're talking everything--adding, subtracting, multiplying, dividing, fractions, decimals... everything!). You'll also take your algebraic skills to new heights by tackling two-step equations. 7th grade is also when you start thinking about probability (which is super important for realizing that casinos and lotteries are really just ways of taking money away from people who don't know probability) and dig deeper into the world of data and statistics. Onward! (Content was selected for this grade level based on a typical curriculum in the United States.)
Community Questions

Rates, proportional relationships, rates

Throughout your day you probably encounter situations where you need to compare two numbers using the same or different units of measurement. Perhaps you want to know how many math problems you can complete in an hour…or how many scoops of ice cream you get out of a gallon bucket. In this set of tutorials you will learn about rate, a special ratio in which two terms are expressed in different units of measurement, and about proportional relationships, how one variable changes in proportion to another. You will practice solving problems and then construct a few of your own.

Negative Numbers

In this group of tutorials, we'll explore the world of negative numbers. Unlike real life where we perceive anything "negative" as being bad, we'll see that negative numbers are quite useful and central to all mathematical concepts. We'll practice adding, subtracting, multiplying, and dividing negative numbers; learn about absolute value, negative exponents, and exponents with negative bases.

Fractions and decimals

I bet if you were asked to give a number, your answer would be whole number. Don't forget about fractions and decimals--they're numbers too only expressed differently. In this set of tutorials we'll demonstrate adding, subtracting, multiplying, and dividing fractions and decimals, as well as converting fractions to decimals and vice versa. Finally, we'll get into some word problems so you can see how often fractions and decimals play a part in our everyday life.

Variables and expressions

In this section, the rubber really hits the road (algebraically speaking, of course). For example, order of operations is the starting point for solving all equations. Learning to combine like terms is equally important. We'll also look at manipulating and interpreting expressions, understanding two step equations, and linear inequalities. Lots of great stuff in this series of tutorials.

Geometry

Why is geometry important? It's all about shapes -- triangles, circles, pyramids, spheres, diamonds, and more. Geometric shapes are all around you, and the world is built with them. In this series of tutorials and exercises you'll become familiar with Euclidean geometry and terms like segments, scale drawings, parts of a circle, area, volume, angles, and geometric figures.

Statistics and probability

We begin our exploration of statistics and probability with a basic understanding of measures of central tendency, including the mean, mode, and median. We'll then look at the importance of sample populations in statistics, in particular that are representative and random. Next up is a discussion of basic probability and the "chances" of a random event occurring. We'll wrap it up looking at different kinds of probability and how we can estimate those, especially when compound events are involved. So get your coins and start flipping. We're going to have some fun!
Statistics and probability
We begin our exploration of statistics and probability with a basic understanding of measures of central tendency, including the mean, mode, and median. We'll then look at the importance of sample populations in statistics, in particular that are representative and random. Next up is a discussion of basic probability and the "chances" of a random event occurring. We'll wrap it up looking at different kinds of probability and how we can estimate those, especially when compound events are involved. So get your coins and start flipping. We're going to have some fun!
All content in “Statistics and probability”

Measures of central tendency

At the base of our understanding of statistics is the concept of data distribution and the measures of central tendency, often referred to as the average of a distribution of values. For instance, have you ever asked your teacher what the average score was on a test? If you have, you wanted to know the value of central tendency. Similar measures are the median and the mode. We'll explain it all for you!

Comparing and sampling populations

When we are trying to make a judgement about a population, it is often impractical (or impossible) to observe every member of the population. Imagine trying to survey all 300+ million Americans to understand the likely outcome of the next presidential election! Because of this, much of statistics is collecting data from a representative and random sample. From the data collected from this random sample we can infer things about the greater population.

Basic probability

Flip a quarter a hundred times. What's the probability that it will turn up heads? Tails? Even if we are unsure about whether something will happen, can we start to be mathematical about the "chances" of an event (essentially realizing that some things are more likely than others) occurring. This set of tutorials will introduce us to the tools that allow us to think about random events and the logic behind comparing, judging, and finding the probabilities of those events. Common Core standards: 7.SP.C.5, 7.SP.C.7a,

Estimating probability

If you know all of the possible outcomes of a trial (and the associated probabilities of each of them), you can find the exact probability. In many situations, however, we don't know this and instead, we estimate the probability based on history of events. That's what we're going to do in this tutorial.

Probability and compound events

What are the chances that you will win against your friend at the game Rock, Paper, Scissors if you play ten times in a row? This gets into a different kind of probability since we are examining possible outcomes of TWO independent events: your play and your friend's. In this group of tutorials, we will explore various facets of probability including compound probability, frequency stability, and probability without equally unlikely events. Common Core Standards: 7.SP.C.8, 7.SP.C.8a, 7.SP.C.8b

Dependent probability

We're shifting our focus away from probabilities based upon independent events, and looking instead at dependent events--which are events that can be affected by previous events. This is one of many types and scenarios involving probability. Let's go!