## Lesson: Writing and Solving Equations

Developing the Concept

Once students practice isolating the specific words in a sentence that indicate operations and expressions, they are ready to write and solve equations.

**Materials:** overhead projector or chalkboard

**Preparation:** Write the word problem on the overhead projector or chalkboard.

**Prerequisite Skills and Concepts:** Students should be familiar with words that indicate operations as well as numbers and should understand that addition and subtraction are inverse operations. They will also need to simplify and evaluate expressions.

Write or project this word problem.

“Tina gave four CDs to her friend Dan. He put them in with his collection that he was donating to a local charity. His CD player was broken and he didn't listen to that kind of music anymore. But Dan's sister asked if she could take three of Tina's CDs. He told her she could, without remembering he had promised to donate at least ten CDs. He checked the box and there were still ten inside. How many CDs were in Dan's collection at the start?”

**Wrap-Up and Assessment Hints**

Assign other word problems and have students practice going through the words and sentences, step by step to create an equation. Remind them that different words are used to indicate operations, expressions, and variables.