Compound Percentages

LO: To solve problems involving compound percentages

Progression:
a) Convert fractions to percentages, and find percentage of amount (grade 2)
b) Calculate the multiplier for increase/decrease (grade 3)
c) Find amount involving compound interest and depreciation (grade 4/5)
d) Find an amount after a repeated percentage change (grade 6)
e) Find the r/n when amount at depreciation/compound interest is given. (grade 7)
f) Solve more complex real life problems involving compound percentages (grade 9)

LO: To solve problems involving compound percentages

Activity-1 (Group):
Discuss this in your group and have a common answer with clear explanation. Neatly provide your response on the available paper.

Would you rather take £1 million for life or a penny that doubles itself every day for 30 days?

LO: To solve problems involving compound percentages

Activity-2 (Group): Discuss these questions in your group and write your thoughts in your mathematics notebook.
a) What do the following key words mean, as used in financial mathematics? interest, rate, principal, time, and amount
b) In simple clear terms, differentiate between simple interest and compound interest. You may include the formula in each case.
c) In what careers are these terms commonly used?

LO: To solve problems involving compound percentages

Activity-3 (Individual): Discuss this in your group and neatly provide your response in your mathematics notebook.
Eliah invests $8500 for 3 years in a savings account. He gets 2.3% per year compound interest. How much money will Eliah have in his savings account at the end of 3 years? Give your answer correct to the nearest dollar.

LO: To solve problems involving compound percentages

Activity-4 (Individual): Discuss this in your group and neatly provide your response in your mathematics notebook.
Tomiwa invests ₤6300 for 3 years in a savings account paying interest. The rate of interest is 1.75% in each of the first two years and 1.5% in the third year.
Work out how much Tomiwa will have in the account at the end of the third year.
Give your answer to 3 significant figures.

LO: To solve problems involving compound percentages

Activity-5 (Individual): Discuss this in your group and neatly provide your response in your mathematics notebook.
Teniayo invests 80 000 Kenyan shillings (KES). She invests the money for 4 years at x% compound interest each year. At the end of 4 years, the total interest she receives is 6151.25KES. Work out the value of x.
Give your answer to 3 significant figures.

LO: To solve problems involving compound percentages

Activity-6 (Individual): Discuss this in your group and neatly provide your response in your mathematics notebook.
Gabriel bought a car. The value of the car when Gabriel bought it was 750000 JPY. At the end of each year, the value of his car had depreciated by 15%.
Work out the value of Gabriel’s car at the end of 3 years. Give your answer correct to the nearest JPY.

LO: To solve problems involving compound percentages

Activity-7 (Group): Discuss this in your group and neatly provide your response on the available paper.
Nicole has two choices - invest ₤2000 in Hekaire Bank (HB) at a rate of 1.5% compound interest for 3 years or invest ₤2000 in Ali Bank (AB) at a rate of 1.5% simple interest for 3 years. These two banks are at the same distance from her home. Which of the banks would you advise her to go to, and why?

LO: To solve problems involving compound percentages

Plenary/Reflection:
What would be the effect if an interest is compounded half yearly, quarterly, monthly or daily?