Lesson Plan

Lesson Plan
Grade: Date: 17/01/2026
Subject: Additional Mathematics
Lesson Topic: Solve equations of the form a^x = b using logarithms or other appropriate methods
Learning Objective/s:
  • Describe the relationship between exponential and logarithmic forms.
  • Apply the logarithmic method to solve ax = b for any positive a ≠ 1 and b > 0.
  • Choose and use an appropriate logarithm base (common, natural, or base‑a) to isolate x.
  • Check solutions for validity and express answers with the correct number of significant figures.
  • Solve simple cases without logarithms by matching exponents or using a graphical approach.
Materials Needed:
  • Projector and screen
  • Whiteboard and markers
  • Student worksheets with practice questions
  • Scientific calculators
  • Printed handout of key logarithm formulas
  • Graph paper
Introduction:

Begin with a quick puzzle: “If 3x = 81, what is x?” Students answer using prior knowledge of powers. Review that the inverse of an exponential function is a logarithm and state the success criteria: students will be able to rewrite ax = b as x = logab and solve it accurately.

Lesson Structure:
  1. Do‑now (5′): Mini‑whiteboard activity solving 3x=81; teacher checks understanding of the power rule.
  2. Mini‑lecture (10′): Present the exponential ↔ logarithmic relationship, derive x = logab, and illustrate with common logarithms.
  3. Guided practice (12′): Work through the natural‑log example (5x=0.2) step‑by‑step; students fill in missing steps on their worksheets.
  4. Independent practice (15′): Students attempt Questions 1‑4 from the worksheet; teacher circulates, prompting use of the general procedure.
  5. Alternative methods (8′): Demonstrate a quick graphical solution using the projector and a graphing calculator.
  6. Check for understanding (5′): Exit ticket – students write the five‑step procedure in their own words.
Conclusion:

Summarise the key steps for solving ax = b and remind students of common pitfalls such as forgetting domain restrictions. Collect the exit tickets to gauge mastery, and assign homework: complete the remaining practice questions and sketch a graph to verify one solution.