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Math

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
A thumbnail for: Ratios, proportions and rates
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Ratios, proportions and rates
A thumbnail for: Negative numbers
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Negative numbers
A thumbnail for: Fractions and decimals
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Fractions and decimals
A thumbnail for: Variables and expressions
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Variables and expressions
A thumbnail for: Geometry
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Geometry
A thumbnail for: Statistics and probability
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Statistics and probability
Statistics and probability

Measures of central tendency

Statistics can be used to gain information about a population by examining a sample of the population; generalizations about a population from a sample are valid only if the sample is representative of that population. The fun must not stop! Common Core Standard: 7.SP.A.1, 7.SP.A.2

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. For example, imaging trying to survey all 300+ million Americans to understand the likely outcome of the next presidential election! Because of this, much of statistics is making estimates about a population based on a random sample. This tutorial introduces you to the idea of what makes a good random sample. I'm sure all of you would enjoy it (but I haven't had the time to ask all of you).

Basic probability

Can I pick a red frog out of a bag that only contains marbles? Is it smart to buy a lottery ticket? 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). This tutorial will introduce us to the tools that allow us to think about random 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.

Compound events

What is the probability of making three free throws in a row (LeBron literally asks this in this tutorial). In this tutorial, we'll explore compound events happening where the probability of one event is not dependent on the outcome of another (compound, independent, events). Common Core Standards: 7.SP.C.8, 7.SP.C.8a, 7.SP.C.8b

Dependent probability

What's the probability of picking two "e" from the bag in scrabble (assuming that I don't replace the tiles). Well, the probability of picking an 'e' on your second try depends on what happened in the first (if you picked an 'e' the first time around, then there is one less 'e' in the bag). This is just one of many, many type of scenarios involving dependent probability.