Lesson Notes By Weeks and Term v4 - SHS 2

Lesson Video

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Performance objectives

• Analyze and model word problems using simultaneous linear equations.
• Solve real-life problems involving numbers and ages.
• Apply strategic reasoning to find solutions.

Lesson summary

In our daily lives in Ghana, we are constantly faced with situations where we have to find unknown quantities based on the information we have. For example, a market woman needs to know the price of individual items when she sells them in bundles, or a parent wants to know the ages of their children based on some relationships between their ages. This lesson gives us the mathematical tools to solve these kinds of practical problems. By learning to translate word problems into equations, we are developing critical thinking and problem-solving skills that are essential not only for passing WASSCE but for making informed decisions in life.

Lesson notes

Introduction (Talk for Learning Strategy - 5 mins): As a class, let's review: What is a linear equation? (An equation whose graph is a straight line, e.g., `x + y = 10`). What are simultaneous linear equations? (A set of two or more linear equations that are true at the same time, for the same variables). What are the three methods we know for solving them? (Elimination, Substitution, and Graphical Method).

Today, we are moving from just solving equations to using them to solve real-world puzzles.

The 5-Step Process for Solving Word Problems: Solving word problems can be easy if you follow a clear, logical process. We will use these five steps for every problem: READ and UNDERSTAND: Read the problem carefully, more than once. Identify what you are asked to find. Underline the key pieces of information. DEFINE VARIABLES: Assign variables (like `x`, `y`, or letters that make sense, e.g., `k` for Kwaku's age) to the unknown quantities you need to find. Write down clearly what each variable represents. *Example:* "Let `x` be the cost of one exercise book. Let `y` be the cost of one pen." TRANSLATE to EQUATIONS: Convert the sentences and relationships from the problem into two mathematical equations. Look for keywords: `sum`, `altogether`, `total` -> Addition (+) `difference`, `less than`, `more than` -> Subtraction (-) `product`, `times`, `of` -> Multiplication (*) `is`, `equals`, `gives`, `results in` -> Equals sign (=) SOLVE the SYSTEM: Use the most convenient method (usually elimination or substitution) to solve the two equations simultaneously. CHECK and INTERPRET: Check your answer by substituting the values back into your original equations. More importantly, check if the answer makes sense in the context of the word problem. (e.g., Age cannot be negative). Write a final sentence that clearly answers the question asked in the problem.

Worked Examples (Modelling):

Evaluation guide

• Analyse, model, and solve word problems of simultaneous linear equations involving
• numbers , age, etc.
• Using Talk for Learning strategy , review with the whole class the concept of linear equations
• involving word problems.