Lesson Notes By Weeks and Term v5 - Grade 12

Lesson Video

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Performance objectives

• Calculate and differentiate between simple and compound interest.
• Compare different loan options.
• Analyse the impact of inflation on investments.
• Calculate future and present values.
• Understand loan amortization schedules.

Lesson summary

This week, we're diving back into the crucial world of loans and investments. Understanding these financial concepts is absolutely essential for navigating life successfully in South Africa. Whether it's securing a loan for further education, buying a car, investing in a small business, or planning for retirement, the ability to make informed financial decisions is a powerful tool. We will revisit the calculations and concepts we learned previously, applying them to more complex scenarios and emphasizing the importance of comparing different options.

Lesson notes

Simple Interest: Simple interest is calculated only on the principal amount of a loan or investment. It's a straightforward way to calculate interest, but it's less common for long-term loans or investments.

Formula: A = P(1 + rt), where: A = Accumulated amount (principal + interest) P = Principal amount r = Interest rate (as a decimal) t = Time (in years)

Compound Interest: Compound interest is calculated on the principal amount and also on the accumulated interest from previous periods. This means you earn interest on your interest, leading to faster growth over time. It is far more prevalent than simple interest in most real-world scenarios.

Formula: A = P(1 + r/n)^(nt), where: A = Accumulated amount P = Principal amount r = Interest rate (as a decimal) n = Number of times interest is compounded per year (e.g., annually, semi-annually, quarterly, monthly) t = Time (in years)

Why it Matters: Understanding the difference is critical. Compound interest works in your favor when investing, but against you when borrowing.