Simple Interest and Problems Involving Saving
Primary 6 · Mathematics
Simple Interest and Problems Involving Saving
Lesson 4 of 5
15 min
Let's begin
Niyonzima gets 500 Frw from his uncle every weekend. He dreams of a 12 000 Frw football. His older sister says, "If you save every coin, you will have it in 24 weeks. But where will you keep the money all that time?"
A budget is a plan for how you will spend and save your money. Write down the money coming in, then list what you must spend, and see what is left to save.
Worked example
Mutesi's family earns 150 000 Frw a month. They plan to spend 60 000 Frw on food, 25 000 Frw on school, 15 000 Frw on transport, 10 000 Frw on water and electricity and 15 000 Frw on other things.
Spending = 60 000 + 25 000 + 15 000 + 10 000 + 15 000 = 125 000 Frw.
Savings each month = 150 000 − 125 000 = 25 000 Frw.
Savings in a year = 25 000 × 12 = 300 000 Frw.
Saving for a goal. Niyonzima's football: 12 000 ÷ 500 = 24 weekends.
| Where | Good points | Weak points |
|---|---|---|
| A tin or piggy bank at home | Easy to reach | No interest; can be lost, stolen or spent too easily |
| A savings group (ikimina) | Members save together every week or month and help each other; some lend to members | Needs trust and good records |
| An Umurenge SACCO | Safe; pays interest; gives loans to members; found in every sector | You must open an account |
| A bank | Safe; pays interest on savings accounts | May charge fees |
| Ejo Heza | A national long-term savings scheme to prepare for old age | The money is kept for the long term |
Money can also be invested, for example in livestock, land or a small business. Investments can grow a lot, but they can also lose value, so they carry more risk than a savings account.
If a relative abroad sends you money, it must be changed into Rwandan francs at the exchange rate. The rate changes every day. If 1 US dollar (USD) = 1 400 Frw, then 50 USD = 50 × 1 400 = 70 000 Frw.
Tip
Pay yourself first. As soon as you receive money, put your savings aside. Then spend what is left, not the other way round.
Answers
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Quick check
Ganza keeps all his savings in a tin at home. What is one weak point of this?