Multiplication and Division of Fractions Mathematics Primary 5 First Term Lesson Notes Week 10
Mathematics Primary 5 First Term Lesson Notes
Week: 10
Subject: Mathematics
Class: Primary 5
Term: First Term
Age: 10 years
Topic: Multiplication of Fractions
Sub-Topics:
- Multiplication of Decimals by Whole Numbers
- Multiplication of Fractions
- Real-Life Problems on Multiplication of Decimals and Fractions
- Quantitative Reasoning
Duration: 40 minutes
Behavioural Objectives:
By the end of the lesson, pupils should be able to:
- Multiply fractions.
- Solve real-life problems involving multiplication of fractions.
- Multiply given decimals by whole numbers.
- Interpret and solve real-life problems involving multiplication of decimals and fractions.
- Solve quantitative aptitude problems related to multiplication of decimals and fractions.
Keywords:
- Fractions
- Decimals
- Multiplication
- Real-life problems
- Quantitative reasoning
Set Induction:
The teacher will begin by discussing common scenarios where multiplication of fractions and decimals is used, such as cooking and shopping, to highlight the importance of these skills.
Entry Behaviour:
Pupils should already know how to perform basic multiplication and understand the concept of fractions and decimals.
Learning Resources and Materials:
- Fraction and decimal charts
- Worksheets for practice
- Visual aids for multiplication
- Whiteboard and markers
Building Background/Connection to Prior Knowledge: The teacher will review basic multiplication and introduce the multiplication of fractions and decimals.
Embedded Core Skills:
- Problem-solving
- Analytical thinking
- Application of mathematical operations
Learning Materials:
- Fraction and decimal charts
- Practice worksheets
- Visual aids
Reference Books:
Lagos State Scheme of Work, Primary 5 Mathematics Textbook
Instructional Materials:
- Fraction and decimal charts
- Worksheets
- Whiteboard and markers
Content:
- Multiplication of Decimals by Whole Numbers
- Multiplying decimals by whole numbers.
- Examples and practice problems.
- Multiplication of Fractions
- Multiplying two fractions.
- Simplifying the result.
- Examples and practice problems.
- Real-Life Problems on Multiplication of Decimals and Fractions
- Applying multiplication of decimals and fractions to real-life scenarios.
- Examples and practice problems.
- Quantitative Reasoning
- Solving quantitative aptitude problems involving multiplication of decimals and fractions.
- Examples and practice problems.
Multiplication of Decimals by Whole Numbers
Multiplying Decimals by Whole Numbers:
- To multiply a decimal by a whole number, multiply the numbers as if they were whole numbers, then place the decimal point in the product. The decimal point should be placed so that there are as many digits to the right of it in the product as there are in the original decimal.
Examples:
- 3.5 × 4 = 14.0
- 2.75 × 3 = 8.25
- 1.6 × 5 = 8.0
- 4.25 × 2 = 8.5
- 6.7 × 3 = 20.1
Class Work:
- 2.4 × 6 = ?
- 5.5 × 4 = ?
- 1.9 × 7 = ?
- 3.3 × 3 = ?
- 4.8 × 5 = ?
Multiplication of Fractions
Multiplying Two Fractions:
- To multiply two fractions, multiply the numerators together to get the new numerator, and multiply the denominators together to get the new denominator. Then, simplify the fraction if possible.
Examples:
- 2/3 × 3/4 = 6/12, which simplifies to 1/2
- 1/2 × 4/5 = 4/10, which simplifies to 2/5
- 3/7 × 2/3 = 6/21, which simplifies to 2/7
- 5/8 × 1/4 = 5/32
- 7/9 × 3/5 = 21/45, which simplifies to 7/15
Class Work:
- 3/5 × 4/7 = ?
- 1/3 × 2/6 = ?
- 7/8 × 3/4 = ?
- 2/9 × 5/6 = ?
- 4/5 × 2/3 = ?
Real-Life Problems on Multiplication of Decimals and Fractions
Applying Multiplication of Decimals and Fractions to Real-Life Scenarios:
- Use multiplication of decimals and fractions in everyday situations like shopping, cooking, or measuring.
Examples:
- If one apple costs $0.75, what is the cost of 6 apples?
- Solution: 0.75 × 6 = $4.50
- A recipe calls for 2/3 cup of sugar. How much sugar is needed if the recipe is doubled?
- Solution: 2/3 × 2 = 4/3, which is 1 1/3 cups
- If a car travels 7.5 miles in an hour, how far will it travel in 3 hours?
- Solution: 7.5 × 3 = 22.5 miles
- You have 5/8 of a cake, and you want to share it equally between 2 people. How much does each person get?
- Solution: 5/8 × 1/2 = 5/16
- A fabric store sells material at $2.50 per meter. How much will 3.5 meters cost?
- Solution: 2.5 × 3.5 = $8.75
Class Work:
- A notebook costs $1.20. What is the total cost of 5 notebooks?
- If 3/4 liter of juice is required for one recipe, how much juice is needed for 3 recipes?
- A bag of rice costs $4.25 per kilogram. What is the cost of 2.5 kilograms?
- If a person walks 2.8 miles every day, how far will they walk in 7 days?
- A length of ribbon is 3/5 meters long. If you have 4 such ribbons, how long is the total length?
Quantitative Reasoning
Solving Quantitative Aptitude Problems Involving Multiplication of Decimals and Fractions:
Examples:
- A container holds 4.75 liters of water. If you fill 6 such containers, how much water will you have?
- Solution: 4.75 × 6 = 28.5 liters
- A car uses 3/4 gallon of fuel per mile. How much fuel will it use for a 10-mile trip?
- Solution: 3/4 × 10 = 7.5 gallons
- If a bottle contains 1.25 liters of juice, how much juice is there in 8 bottles?
- Solution: 1.25 × 8 = 10 liters
- A builder needs 5/6 tons of cement for one section of a wall. How much is needed for 4 sections?
- Solution: 5/6 × 4 = 20/6, which simplifies to 3 1/3 tons
- If a machine produces 2.5 parts every minute, how many parts will it produce in 15 minutes?
- Solution: 2.5 × 15 = 37.5 parts
Class Work:
- A worker earns $12.50 per hour. How much will they earn in 8 hours?
- A car uses 3/5 of a gallon of fuel for every 2 miles. How much fuel is needed for 10 miles?
- If a packet of seeds costs $2.75, what is the cost of 7 packets?
- A runner covers 1.4 miles in 12 minutes. How far will they run in 36 minutes?
- If 3/4 of a cake is shared among 4 people, how much does each person get?
Assessment
- Multiply 1/2 by 3/4. The result is __________.
a) 3/8
b) 3/4
c) 1/2
d) 1/4 - 0.6 multiplied by 3 is __________.
a) 1.8
b) 1.6
c) 1.2
d) 0.8 - Multiply 2/3 by 3/5. The result is __________.
a) 6/15
b) 2/5
c) 4/5
d) 1/2 - 0.75 multiplied by 4 is __________.
a) 3
b) 2
c) 2.5
d) 1.5 - Multiply 5/8 by 2. The result is __________.
a) 10/8
b) 5/4
c) 1/2
d) 5/16 - 0.25 multiplied by 8 is __________.
a) 2
b) 1.5
c) 2.5
d) 3 - Multiply 3/5 by 4/7. The result is __________.
a) 12/35
b) 4/35
c) 12/7
d) 3/7 - 0.9 multiplied by 5 is __________.
a) 4.5
b) 3.5
c) 5.5
d) 4 - Multiply 7/8 by 3/4. The result is __________.
a) 21/32
b) 7/32
c) 21/24
d) 3/8 - 0.1 multiplied by 9 is __________.
a) 0.9
b) 0.1
c) 1
d) 0.5 - Multiply 3/4 by 1/2. The result is __________.
a) 3/8
b) 1/4
c) 1/2
d) 1/8 - 0.05 multiplied by 10 is __________.
a) 0.5
b) 0.05
c) 1
d) 0.1 - Multiply 1/3 by 2/9. The result is __________.
a) 2/27
b) 1/9
c) 2/3
d) 2/9 - 0.7 multiplied by 2 is __________.
a) 1.4
b) 1
c) 0.9
d) 0.5 - Multiply 4/9 by 3/5. The result is __________.
a) 12/45
b) 4/15
c) 12/9
d) 12/15
Class Activity Discussion
- Q: How do you multiply two fractions?
A: Multiply the numerators together and the denominators together. - Q: What is the first step when multiplying a fraction by a whole number?
A: Convert the whole number to a fraction by giving it a denominator of 1. - Q: How do you multiply decimals by whole numbers?
A: Multiply the decimal as if it’s a whole number, then place the decimal point in the product. - Q: How can you simplify the product of two fractions?
A: Divide both the numerator and denominator by their greatest common divisor. - Q: Why is it important to understand how to multiply fractions and decimals?
A: It’s used in real-life situations, such as cooking, shopping, and calculating discounts. - Q: How do you multiply a decimal by 10 or 100?
A: Move the decimal point to the right by 1 place for 10 and by 2 places for 100. - Q: What should you do if you get a fraction as a product?
A: Simplify it if possible. - Q: How do you multiply a mixed number by a fraction?
A: Convert the mixed number to an improper fraction, then multiply. - Q: How do you solve real-life problems using multiplication of fractions?
A: Translate the problem into a mathematical expression involving fractions and multiply. - Q: How is multiplying decimals useful in real life?
A: It helps in calculating prices, measurements, and other quantities accurately. - Q: What is the significance of placing the decimal point correctly in multiplication?
A: It ensures the accuracy of the product. - Q: What is the role of quantitative reasoning in solving problems with fractions and decimals?
A: It helps in logically analyzing and solving complex problems. - Q: How can you check your answer after multiplying fractions?
A: Simplify the fraction and compare it with the expected result. - Q: Why should fractions be simplified after multiplication?
A: To make the answer more understandable and easier to use. - Q: What is the importance of multiplying fractions and decimals in academic work?
A: It builds a strong foundation for more advanced mathematical concepts and real-world applications.
Presentation:
Step 1: Review basic multiplication and introduce multiplication of fractions.
Step 2: Demonstrate how to multiply decimals by whole numbers.
Step 3: Solve real-life problems involving multiplication of fractions and decimals.
Teacher’s Activities:
- Explain and demonstrate multiplication of fractions and decimals.
- Provide examples and practice problems.
- Guide pupils through real-life problem scenarios.
Learners’ Activities:
- Participate in solving multiplication problems.
- Complete worksheets with fraction and decimal problems.
- Practice quantitative reasoning problems.
Assessment:
- Multiply fractions and decimals by whole numbers.
- Solve real-life problems involving multiplication of fractions.
- Apply the learned concepts in quantitative reasoning.
Evaluation Questions:
- Multiply 1/3 by 2/5.
- What is 0.8 multiplied by 4?
- Multiply 7/10 by 3/8.
- What is 1/2 multiplied by 3/4?
- Solve: 0.5 multiplied by 6.
- Multiply 2/3 by 3/5.
- What is 0.9 multiplied by 2?
- Multiply 3/4 by 1/3.
- Solve: 0.25 multiplied by 8.
- Multiply 4/9 by 2/7.
Conclusion:
The teacher will review the lesson, correct any errors, and ensure that pupils understand the process of multiplying fractions and decimals. Pupils will discuss the importance of these skills in everyday life.