# Algebra 1

## 2 - Make sure you know this stuff

Algebra is fun and it's the first really exciting math you do. But, you need to make sure you understand some of the basics first.

Go through these videos and make sure you understand these topics before you continue on. Or, continue on, and come back and learn things you missed as you go along.

- Addition and subtraction are inverse operations, which means that addition can undo subtraction and subtraction can undo division. Addition has a commutative property, so 5+4 is the same as 4+5.
- Multiplication and division are inverse operations. Division can undo multiplication and multiplication can undo division. Multiplication has a commutative property, so 5x4 gives the same answer as 4x5.
- Decimal numbers can be converted to fractions.
- Any fractions can be converted to decimal numbers.
- Working with percents
- Exponents and roots are inverse operations. Neither exponents or roots are commutative.
- Learn about geometry, including angles, degrees, points, lines, planes,perimeter, and area.
- What are ratios and rates? What are proportions?
- What are the order of operations?
- What is factoring?
- What is a prime number?