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

# Pre-algebra

Community Questions
Applying mathematical reasoning
You already have many tools in your mathematical toolkit. In this topic, you'll use these in settings that you're likely to encounter in the real world!
All content in “Applying mathematical reasoning”

This tutorial is less about statistics and more about interpreting data--whether it is presented as a table, pictograph, bar graph or line graph. Good for someone new to these ideas. For a student in high school or college looking to learn statistics, it might make sense to skip (although it might not hurt either).

### Multi-step word problems

The world seldom gives you two numbers and tells you which operation to perform. More likely, you'll be presented with a bunch of information and you (yes, YOU) need to make sense of them. This tutorial gives you practice doing exactly that. When watching videos, pause and attempt it before Sal. Then work on as many problems as you want in the exercise at the end of the tutorial.

### Inequalties : Greater than and less than basics

Equality is usually a good thing, but the world is not a perfect place. No matter how hard we try, we can't help but compare one thing to another and realize how unequal they may be. This tutorial gives you the tools to do these comparisons in the mathematical world (which we call inequalities). You'll become familiar with the "greater than" and "less than symbols" and learn to use them.

### Cross topic arithmetic

You've probably been learning how to do arithmetic for some time and feel pretty good about it. This tutorial will make you feel even better once by showing you a bunch of examples of where it can be applied (using multiple skills at a time). Get through the exercises here and you really are an arithmetic rock star!

### Number patterns

Let's explore how numbers can grow in different ways and use what we learn to figure out where they can go. We think you'll find this tutorial on number patterns more fun that you do :)

### Constructing numeric expressions

Let's construct and interpret expressions from word problems. We can also think about what the effects of parentheses are.

### Binary and hexadecimal number systems

Most of us are use to using the digits 0-9 to represent numbers in the base-10 (decimal)number system. In this tutorial, we'll see that is just one of many (really infinite) number systems. In particular, we will focus on the binary (base-2) and hexadecimal (base-16) systems.