DATE: *September 15, 2008*

TOPIC: *two-step equations*

OBJECTIVE: *we will be able to solve two-step equations.*

WHAT IS AN EQUATION?

An **equal sign (=)** is like a scale: the things on either side are exactly the same. For example, 2+2 = 4. If I have $2, and my friend Mark has $2, that is the same as having a total of $4.

In an **equation,** we need to figure out a **missing number** in order to figure out how to make the things on either side of the equal sign exactly the same. That **missing number is called a VARIABLE. **We use letters to show a variable. For example, 2 + n = 4. The "n" is our **missing number. **It is our **variable.**

When we talk about **solving an equation, **all we really want to do is **find out what number the variable is. **For example, in the equation 2+ n = 4, we know that the variable is equal to the number 2. We know this because if we took out the "n" and replaced it with a "2", we would get 2 + 2 = 4. In this case, both sides of the equation are equal. That's exactly what we want to find!

UNDERSTANDING QUESTIONS:

1. The two things on either side of an equal sign (=) are always ____________.

2. In an equation, we are trying to find a ________________.

3. We represent variables with ______________.