Lesson Notes By Weeks and Term v3 - Primary 6
(b) Conversion of currencies
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(b) Conversion of currencies
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Subject: General Mathematics
Class: Primary 6
Term: 2nd Term
Week: 4
Theme: Measurement
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Use a calculator to convert from one currency to another; Solve problems on quantitative aptitude based on converting from one currency to another.
A. Currency: A currency is a system of money used in a particular country. It serves as a medium of exchange for goods and services.
Examples in Nigeria: The official currency of Nigeria is the Naira (₦).
Examples of Foreign Currencies: United States Dollar (USD or $) British Pound Sterling (GBP or £) Euro (EUR or €) Ghanaian Cedi (GHS or ₵) West African CFA franc (XOF) – used in countries like Benin, Niger, Togo. South African Rand (ZAR or R)
B. Exchange Rate: The exchange rate is the value of one country's currency in relation to another country's currency. It tells us how much of one currency we can get for another. Exchange rates are constantly changing but are usually provided for conversion exercises.
Example: If 1 US Dollar (USD) = ₦1500 (Nigerian Naira), this means that for every 1 Dollar, you can get 1500 Naira, or if you have 1500 Naira, you can buy 1 Dollar.
C. Principles of Currency Conversion: The core idea behind currency conversion is simple multiplication or division using the exchange rate.
Rule 1: Converting from a Larger Unit (in terms of local value) to a Smaller Unit (in terms of local value) or from Foreign Currency to Local Currency. When you have foreign currency and want to convert it to Naira, you generally multiply the amount of foreign currency by the exchange rate (Naira per unit of foreign currency).
Analogy:* If 1 bag of rice costs ₦10,000, 3 bags will cost 3 x ₦10,
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0. Similarly, if 1 USD is ₦1500, then 5 USD will be 5 x ₦
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0. Example 1: Convert $500 to Naira if the exchange rate is $1 = ₦1,
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0. Step 1: Identify the given amount: $
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0. Step 2: Identify the exchange rate: $1 = ₦1,
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0. Step 3: Since we are converting from Dollars to Naira, we multiply.
Calculation: 500 × ₦1,450 = ₦725,000 Answer: $500 is equal to ₦725,
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0. Rule 2: Converting from a Smaller Unit (in terms of local value) to a Larger Unit (in terms of local value) or from Local Currency to Foreign Currency. When you have Naira and want to convert it to foreign currency, you generally divide the amount in Naira by the exchange rate (Naira per unit of foreign currency).
Analogy:* If 1 bag of rice costs ₦10,000, and you have ₦30,000, you can buy ₦30,000 ÷ ₦10,000 = 3 bags. Similarly, if ₦1500 is 1 USD, and you have ₦7,500, you can buy ₦7,500 ÷ ₦1500 = 5 US
D. Example 2: Convert ₦450,000 to British Pounds (£) if the exchange rate is £1 = ₦1,
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0. Step 1: Identify the given amount: ₦450,
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0. Step 2: Identify the exchange rate: £1 = ₦1,
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0. Step 3: Since we are converting from Naira to Pounds, we divide.
Calculation: ₦450,000 ÷ ₦1,800 = 250 Answer: ₦450,000 is equal to £
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0. D.
Using a Calculator: The performance objectives explicitly state the use of a calculator. Teachers should ensure students have access to basic calculators and demonstrate how to input numbers and perform multiplication and division. This promotes efficiency and accuracy, especially with larger numbers or rates with decimal places.
Phase 1: Introduction and Concept Building (15 minutes)
Teacher Activity: Begins by asking students if they have ever seen foreign money or heard of people exchanging money (e.g., travelers, family members abroad). Introduces the concept of "currency" and "exchange rate" using simple language and relatable Nigerian examples (e.g., comparing the value of a N100 note in Nigeria to what a $1 note might buy in the USA). Writes down common currencies and their symbols (Naira, Dollar, Pound, Euro, CFA) on the board. Explains the idea of an exchange rate using a current, simplified example, e.g., "Today, 1 US Dollar is equal to about NGN 1,400." Emphasises the importance of knowing which currency is being converted to which, and therefore whether to multiply or divide. Demonstrates how to use a basic calculator for multiplication and division.
Student Activity: Listens attentively and participates in brief discussions about money and foreign countries. Observes the currencies and symbols written on the board. Asks clarifying questions about currency and exchange rates. Practices basic multiplication and division on their calculators as demonstrated by the teacher.
Phase 2: Guided Examples and Practice (20 minutes)
Teacher Activity: Presents Example 1 (Foreign to Local currency conversion) on the board. Explains each step clearly, guiding students on when to multiply. Walks students through the calculation using the calculator. Presents Example 2 (Local to Foreign currency conversion) on the board. Explains each step clearly, guiding students on when to divide. Walks students through the calculation using the calculator. Provides a few more similar problems and asks students to solve them in pairs or small groups using their calculators, circulating to offer support.
Student Activity: Copies the examples into their notebooks. Follows the teacher's steps to solve the examples on their calculators. Works in pairs or small groups to solve additional practice problems, discussing strategies and helping each other. Presents their solutions on the board when called upon.
Phase 3: Quantitative Aptitude Problems (15 minutes)
Teacher Activity: Introduces a simple quantitative aptitude problem involving currency conversion (e.g., comparing the cost of an item bought locally versus imported, after conversion). Guides students on how to break down the problem: identify the amounts, the exchange rates, and the required operations (convert, then compare/subtract/add). Emphasises clear presentation of steps. Provides another problem for students to attempt independently or in groups.
Student Activity: Listens to the explanation of quantitative aptitude problems. Attempts to solve the problems, applying the conversion rules and calculator skills. Discusses solutions within groups and presents their findings.
Phase 4: Consolidation and Wrap-up (5 minutes)
Teacher Activity: Reviews the key concepts: currency, exchange rate, when to multiply, when to divide. Addresses any remaining questions or common errors. Assigns independent practice questions as homework.
Student Activity: Participates in the review, asking any final questions. Records homework assignment. (Teacher to guide students through these problems, encouraging calculator use for each step.)
Question 1: Mrs. Bala wants to convert ₦280,000 into US Dollars for her trip to America. If the exchange rate is $1 = ₦1,400, how many US Dollars will she get?
Solution 1: Understanding the problem: Mrs. Bala has Naira and wants to buy Dollars. This means converting from Naira to Dollars.
Rule to apply: When converting from local currency (Naira) to foreign currency (Dollars), we divide the Naira amount by the exchange rate.
Calculation: Amount in Naira = ₦280,000 Exchange rate = $1 = ₦1,400 Amount in Dollars = ₦280,000 ÷ ₦1,400 Using a calculator: 280000 ÷ 1400 = 200 Answer: Mrs. Bala will get $
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0. Question 2: A Nigerian trader bought goods worth £350 from the U
K. If the exchange rate is £1 = ₦1,850, how much did the goods cost him in Naira?
Solution 2: Understanding the problem: The trader bought goods in British Pounds and wants to know the cost in Naira. This means converting from Pounds to Naira.
Rule to apply: When converting from foreign currency (Pounds) to local currency (Naira), we multiply the foreign currency amount by the exchange rate.
Calculation: Amount in Pounds = £350 Exchange rate = £1 = ₦1,850 Cost in Naira = £350 × ₦1,850 Using a calculator: 350 × 1850 = 647,500 Answer: The goods cost the trader ₦647,
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0. Question 3: Adamu wants to buy a new pair of shoes. He saw them online for $
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5. In Nigeria, a similar pair costs ₦70,
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0. If the exchange rate is $1 = ₦1,550, which option is cheaper for Adamu?
Solution 3: Understanding the problem: This is a quantitative aptitude problem.
Adamu needs to compare two prices: one in Dollars and one in Naira. To compare, both must be in the same currency. Let's convert the Dollar price to Naira.
Step 1: Convert the online price to Naira. Online price = $45 Exchange rate = $1 = ₦1,550 Cost in Naira = $45 × ₦1,550 Using a calculator: 45 × 1550 = 69,750 So, the online shoes cost ₦69,
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0. Step 2: Compare the converted price with the local price. Online shoes cost = ₦69,750 Local shoes cost = ₦70,000 Step 3: Determine which is cheaper. ₦69,750 is less than ₦70,
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0. Answer: The online shoes for $45 (which is ₦69,750) are cheaper for Adamu.
A. Remediation (for struggling learners): Simplified Visual Aids: Provide a clear chart with a few common exchange rates (e.g., $1 = ₦X, £1 = ₦Y). Use simple, whole numbers for amounts to be converted.
One-on-One/Peer Support: Pair struggling learners with more capable peers for guided practice. The teacher should also provide direct individual assistance, focusing on identifying whether to multiply or divide.
Manipulatives/Role-play: Use mock foreign currency notes alongside Naira notes. Engage in a simple role-play of "currency exchange" where students physically exchange notes based on a given rate, which can help solidify the multiplication/division concept.
Step-by-Step Prompts: Provide worksheets with blanks to guide them through each step of the conversion process (e.g., "Amount in Naira: ____; Exchange Rate: ____; Operation (Multiply/Divide): ____; Calculated amount: ____").
B. Extension (for high-achieving learners): Real-time Exchange Rates: Challenge students to research current live exchange rates online (e.g., from the Central Bank of Nigeria website or reputable financial news sites) and perform conversions using those rates, which often include decimal places.
Multi-currency Conversion: Introduce scenarios requiring multiple conversions (e.g., "Convert Naira to US Dollars, then convert those Dollars to British Pounds, given two exchange rates.").
Profit/Loss Calculation: Present problems where students calculate the profit or loss made by someone who exchanges currency at one rate and converts it back at a different rate, simulating a real-world investment or trading scenario.
Comparing Different Exchange Sources: Ask students to compare exchange rates from different sources (e.g., bank vs. Bureau de Change) and determine which offers a better deal for buying or selling a specific currency.
Saving for International Travel/Schooling: A Nigerian family planning a vacation to Dubai (which uses UAE Dirham, usually pegged to USD) or sending a child to study in Canada (Canadian Dollar) needs to understand how much Naira they need to save to meet their foreign currency expenses. This topic helps them calculate required savings.
Evaluating Business Opportunities: Local traders who consider importing goods from neighboring countries (e.g., Togo, Benin using CFA franc) or distant countries (e.g., China using Yuan, often converted via USD) must convert the foreign cost to Naira to determine their profit margins and overall feasibility. This informs their pricing strategies in the local market.
Understanding Remittances and Donations: Many Nigerian families receive financial support from relatives in the diaspora (e.g., UK, USA). Understanding currency conversion allows them to accurately calculate the Naira value of the money they receive, helping them manage their budgets effectively. Similarly, when international organisations donate funds in foreign currencies, local beneficiaries need to convert it to Naira for use.