This lesson was shared in March/April 2009
Main Topic: Introduction to Algebra
Sub-Topic: Magic with Algebra (Lesson #3)
Duration: 1 hour
Lesson Plan

Pease see suggested ways to rephrase under "Activities" column & please respond to the questions under the "Technology Use in T&L"

Lesson Objectives
Demonstration of Student Outcomes
Essential Questions
Materials and Resources
Technology Use in T&L
Opening Activity (5-10 min)
  1. Students are to access the blog for this lesson.
  2. Students are given 5 min to play a mind reader game called "Ghost Whisperer"
Suggestion (combining 1 & 2)
  1. On their own, students attempt the "Ghost Whisperer" activity from the blog. Get them to write down the numbers they used as they will help to them uncover the mystery later.
Intellectual Curiosity
  1. What are the assumptions made before forming algebraic expression?
  2. How do we interpret algebraic notation?
  3. What is the difference between variables and constants/ coefficients
The resources are used to arouse students' curiosity.
Blog serves as a resource
No baseline skills involved here.

[Real World Motivation]
Main Lesson (40 min)
  1. Students are divided into groups of 3. In their groups, they have to use algebraic expression to unveil the secret behind the "Ghost Whispher" [5 min]
  2. Students are to post their findings through the "comments" in this lesson blog [5 min]
  3. Teacher goes through the findings and reinforces the use of symbols and assumptions algebra [10 min]


  1. In groups of 3, students will use the numbers they have tested and re-visit the steps they followed in the activity.
  2. They will look out for patterns, discuss to explain the mystery. From the specifics, students should be able to draw out common patterns as they work out the steps (in the "Ghost Whisperer").
  3. Using symbols, they would craft the rule to explain how the "Ghost Whisperer" work. (Generalisation)

[Problem Extraction]
  1. Teacher facilitates the next mind reader game "I Know What Digit (Number?) You've Hidden" with 3-digit number. Students, in the same group, response to teachers' instructions in this game. [10 min]
  2. Using the techniques they learnt in the previous activity, the group unpack the mystery and use algebra to explain how the mechanics work.
[Learning through Variation]
  1. Teacher goes through the use of algebra in this game "I Know What Digit You've Hidden". [10 min] Can consider getting another group to walk the class through. Engage the class to provide feedback if the steps/ explanations are logical.
  2. Highlight real world applications to students - pattern observation & prediction.
[Real World Application]
  • Critical Thinking
  • Communication
  • Collaborative Skills
  1. How do we evaluate an algebraic expression?
  2. How do we manipulate an algebraic expression?
  3. How do we simplify an algebraic expression?
GoogleDoc 1
PowerPoint slide that explains the algebra behind "Ghost Whisperer"

GoogleDoc 2
As the task is unlikely to generate multiple explanations, inputs from the groups is likely to be similar.
Moreover, because of the small class size and students are already put in group discussions, we could elicit inputs from various groups quite easily.

Consider inviting a group to present their explanation and walk the class through the 2 stages in Induction:
- Drawing out patterns from specifics
- Generalise and test
This process will also help students understand better (and reinforces) what's meant by "Induction" (which is useful when it comes to "Proofs" in upper secondary).

**Closure & Summary of Lesson Takeaways (10 min)
  1. Teacher consolidates the concept of variables and algebraic expressions learnt in this lesson.
  2. Teacher presents few more examples on how to translate simple real-world situations into algebraic expression.
  3. Students are asked to find out 2 examples of the applications of algebraic expression in their daily life and write a personal Maths Journal with 100 to 150 words in length.
**[Extensions and Connections]
  • Intellectual Curiosity
  • Critical Thinking
  • Collaborative Skills
    • Communication
  1. What are the assumptions made before forming algebraic expression?
  2. How do we manipulate an algebraic expression?
  3. How do we simplify an algebraic expression?
Maths Journal on real world situations that algebraic expressions are used.
What are we going to do with these journals? Going to assess? (Rubrics?)

Will need a task for students to demonstrate their understanding and being able to apply the skills (the alegebra involved, reasoning & induction).

  • Direct students to website that has a number of such msyteries that could be explained mathematically (alegbraically). Get them to pick one, test it out and explain the way they learnt during the lesson.
  • They could post the "mystery" and their explanation in the class blog.
  • The 3 remaining members will evaluate and provide feedback to the post.
  • In this manner, each student will get to apply once (as the 1st person) and go through similar experience (while checking their peers' work).
Briefly describe the purpose of using blogs in this concluding activiites. Will students likely to encounter technical challenges when blog is chosen (i.e. other tools might be a better choice)?