Lesson Plan: Evaluating Expressions

Subject: Mathematics Topic: Number, Money, and Measure Level: Second Level (Scottish Curriculum)

Desired Outcome: I can apply my knowledge of number facts to solve problems where an unknown value is represented by a symbol or letter.

Lesson Objectives: 1. Understand the concept of evaluating expressions. 2. Apply knowledge of number facts to solve problems involving unknown values represented by symbols or letters. 3. Develop problem-solving skills by evaluating expressions in real-life scenarios.

Resources: 1. Whiteboard or blackboard 2. Markers or chalk 3. Worksheets with expressions to evaluate 4. Calculators (optional)

Introduction (10 minutes): 1. Begin the lesson by asking students if they have ever seen or used expressions in mathematics. 2. Discuss the meaning of an expression and provide examples, such as 2 + 3 or 4 × 5. 3. Explain that today’s lesson will focus on evaluating expressions, which means finding the value of the expression when given specific numbers.

Development (25 minutes): 1. Write a simple expression on the board, such as 3 + 4. 2. Ask students to solve the expression and share their answers. 3. Discuss the correct answer (7) and explain that we can evaluate expressions using number facts. 4. Introduce the concept of unknown values represented by symbols or letters, such as x or y. 5. Provide examples of expressions with unknown values, such as 2x + 5 or 3y - 2. 6. Guide students through the process of evaluating expressions by substituting known values for the unknowns. - For example, if x = 3, then 2x + 5 becomes 2(3) + 5 = 6 + 5 = 11. 7. Practice evaluating expressions together as a class, using different examples and unknown values. 8. Provide worksheets with expressions for students to solve independently or in pairs. 9. Circulate the classroom to provide assistance and monitor progress.

Application (20 minutes): 1. Engage students in real-life scenarios where evaluating expressions is necessary. 2. Present word problems that require students to identify the unknown value and evaluate the expression to find the solution. - For example, “Sarah has x number of apples. If she gives away 3 apples, how many apples does she have left? Evaluate the expression x - 3.” 3. Allow students to work individually or in pairs to solve the word problems. 4. Encourage students to explain their reasoning and share their solutions with the class. 5. Discuss the different strategies used by students to evaluate the expressions and solve the problems.

Conclusion (5 minutes): 1. Recap the main points of the lesson, emphasizing the ability to apply knowledge of number facts to solve problems with unknown values represented by symbols or letters. 2. Highlight the importance of evaluating expressions in real-life situations. 3. Address any remaining questions or concerns from students. 4. Assign relevant homework exercises to reinforce the concept of evaluating expressions.

Note: The lesson plan can be adjusted based on the specific needs and abilities of the students.