Addition and Subtraction: From Whole Numbers to Decimals Mathematics Primary 6 First Term Lesson Notes Week 2

Mathematics Lesson Plan: Week 2

Subject: Mathematics
Class: Primary 6
Term: First Term
Week: 2
Age: 10-11 years
Topic: Addition and Subtraction of Numbers
Sub-Topics:
(a) Whole Numbers
(b) Decimal Fractions
(c) Real Problems on Addition and Subtraction of Numbers
(d) Quantitative Reasoning

Duration: 60 minutes

Behavioral Objectives:
By the end of the lesson, pupils should be able to:

1. Add any 4-10 digit numbers and write the answers in words.
2. Subtract any 4-10 digit numbers and write the answers in words.
3. Add any decimal fractions and write the answers in words.
4. Subtract any decimal fractions and write the answers in words.
5. Solve quantitative reasoning problems related to the addition and subtraction of numbers.

Keywords: Addition, Subtraction, Decimal Fractions, Whole Numbers, Quantitative Reasoning

Set Induction:
Start the lesson by asking the students if they ever had to calculate large amounts of money when buying or selling something. Introduce how addition and subtraction of large numbers and decimal fractions are essential in everyday life, especially in handling money.

Entry Behavior:
Students are familiar with basic arithmetic operations, including simple addition and subtraction of smaller numbers.

Learning Resources and Materials:

• Flashcards with large numbers and decimal fractions
• Number line charts
• Place value charts
• Worksheets for practice
• Examples of quantitative reasoning problems

Building Background/Connection to Prior Knowledge:
Revisit the concept of place value and its importance in adding and subtracting larger numbers. Discuss previous experiences with adding and subtracting smaller numbers and relate these to the day’s lesson on larger numbers and decimal fractions.

Embedded Core Skills:

• Critical Thinking
• Problem-Solving
• Numeracy Skills

Learning Materials:

• Lagos State Scheme of Work
• Mathematics textbooks
• Interactive whiteboard

Instructional Materials:

• Flashcards
• Place value charts
• Worksheets

Content

1. Addition and Subtraction of Whole Numbers:

• To add 4-10 digit numbers, align the numbers by their place value (units, tens, hundreds, etc.), starting from the rightmost digit.
• Add each column of digits, moving from right to left. Carry over any extra value to the next column.
• To subtract, align the numbers similarly, ensuring that the larger number is on top.
• Subtract each column of digits, borrowing from the next column if needed.
• Example:
  • Addition: 56,789 + 34,567 = 91,356 (Ninety-one thousand, three hundred fifty-six)
  • Subtraction: 123,456 – 23,789 = 99,667 (Ninety-nine thousand, six hundred sixty-seven)

2. Addition and Subtraction of Decimal Fractions:

• Align the decimal points of the numbers being added or subtracted.
• Add or subtract each digit column as with whole numbers.
• Example:
  • Addition: 45.67 + 12.89 = 58.56 (Fifty-eight point five six)
  • Subtraction: 67.89 – 34.56 = 33.33 (Thirty-three point three three)

3. Real Problems on Addition and Subtraction:

• Apply the above techniques to solve real-life problems such as calculating total prices, change received, or differences in measurements.
• Example: If you have ₦125.45 and you spend ₦79.30, how much do you have left? (₦46.15)

4. Quantitative Reasoning:

• Solve problems that require logical thinking and application of addition and subtraction in different contexts.
• Example: If a number is increased by 234 and the result is 567, what was the original number? (Answer: 333)

Evaluation Questions

1. Add 456,789 and 123,456. The answer is ______.
   a) 580,245 b) 579,245 c) 590,245 d) 569,245
2. Subtract 234,567 from 678,901. The answer is ______.
   a) 444,334 b) 454,334 c) 444,444 d) 445,344
3. Add 78.56 and 34.78. The answer is ______.
   a) 113.34 b) 112.34 c) 123.34 d) 113.44
4. Subtract 123.45 from 567.89. The answer is ______.
   a) 444.44 b) 445.44 c) 444.34 d) 446.44
5. What is the sum of 7,890 and 12,345?
   a) 20,235 b) 20,135 c) 20,255 d) 20,245
6. If you subtract 12.34 from 45.67, you get ______.
   a) 33.33 b) 32.33 c) 34.33 d) 31.33
7. Add 234.56 and 123.45. The answer is ______.
   a) 358.01 b) 358.00 c) 358.02 d) 357.01
8. Subtract 45,678 from 123,456. The answer is ______.
   a) 77,778 b) 77,878 c) 78,778 d) 78,678
9. Add 678.90 and 321.10. The answer is ______.
   a) 1,000.00 b) 999.00 c) 1,001.00 d) 1,100.00
10. Subtract 234.56 from 789.01. The answer is ______.
    a) 554.45 b) 554.55 c) 553.45 d) 553.55
11. Add 4,567,890 and 1,234,567. The answer is ______.
    a) 5,802,457 b) 5,802,557 c) 5,803,457 d) 5,802,467
12. Subtract 567.89 from 1,234.56. The answer is ______.
    a) 666.67 b) 666.77 c) 666.57 d) 665.77
13. If you add 345.67 and 654.32, the sum is ______.
    a) 999.99 b) 1,000.99 c) 1,001.99 d) 999.89
14. Subtract 234,567 from 345,678. The answer is ______.
    a) 111,101 b) 111,111 c) 111,221 d) 110,101
15. Add 123,456 and 654,321. The answer is ______.
    a) 777,777 b) 777,887 c) 778,887 d) 776,777

Class Activity Discussion

1. Q: How do you align numbers for addition?
   A: Align the numbers by their place value, starting from the rightmost digit.
2. Q: What should you do if the sum of a column is more than 9?
   A: Carry over the extra value to the next column.
3. Q: How do you subtract large numbers?
   A: Align the numbers by place value, subtract each column from right to left, and borrow if necessary.
4. Q: What is the first step in adding decimal fractions?
   A: Align the decimal points.
5. Q: How do you handle borrowing in subtraction?
   A: Borrow from the next column to the left if the digit in the top row is smaller than the digit below.
6. Q: Can you add and subtract decimal fractions the same way as whole numbers?
   A: Yes, as long as you align the decimal points.
7. Q: What is the sum of 1.25 and 2.75?
   A: The sum is 4.00.
8. Q: How do you write the answer to 1,234 + 567 in words?
   A: One thousand, eight hundred and one.
9. Q: What is the difference between 5.67 and 2.34?
   A: The difference is 3.33.
10. Q: How do you solve real-life problems involving subtraction?
    A: Subtract the given values, ensuring that the larger number is always on top.
11. Q: What is 2.5 + 3.5 in words?
    A: Six point zero.
12. Q: How do you solve quantitative reasoning problems?
    A: Understand the problem, decide which operations to use, and solve it step by step.
13. Q: Why is it important to align the numbers by place value?
    A: It ensures accuracy in addition and subtraction.
14. Q: What do you do if the decimal points do not align?
    A: Add zeros to ensure the decimal points align.
15. Q: What is the next step after solving a subtraction problem?
    A: Check your work to make sure the answer is correct.

Presentation

Step 1: Revising the Previous Topic

• Start the lesson by reviewing the basic concepts of addition and subtraction.
• Recall how to add and subtract smaller numbers and discuss any difficulties the pupils encountered.

Step 2: Introducing the New Topic

• Introduce the concept of adding and subtracting larger numbers (4-10 digits) and decimal fractions.
• Explain the steps involved in these operations and solve some examples on the board.

Step 3: Allowing Pupils to Contribute and Correcting Them as Necessary

• Provide the pupils with practice problems, and ask them to solve these individually or in pairs.
• Encourage them to explain their reasoning and methods to the class.
• Correct any mistakes and reinforce the correct procedures.

Teacher’s Activities

• Demonstrate how to add and subtract large numbers and decimal fractions.
• Provide real-life examples and quantitative reasoning problems.
• Assist pupils in solving problems on the board and during practice sessions.

Learners’ Activities

• Participate actively in the lesson by solving given problems.
• Work individually or in pairs to complete the worksheets.
• Ask questions whenever necessary to clarify doubts.

Assessment

• Provide exercises for pupils to solve both in class and as homework.
• Observe their ability to add and subtract large numbers and decimal fractions.
• Assess their understanding through quantitative reasoning problems.

10 Evaluation Questions

1. Add 987,654 and 123,456. Write the answer in words.
2. Subtract 234,567 from 890,123. Write the answer in words.
3. Add 123.45 and 678.90.
4. Subtract 45.67 from 123.45.
5. Solve: 1,234 + 5,678.
6. If a person has ₦1,000 and spends ₦345.67, how much is left?
7. Add 7,654 and 3,210.
8. Subtract 345,678 from 1,234,567.
9. Solve: 987.65 + 432.10.
10. What is the result when you subtract 2.34 from 5.67?

Conclusion

• Review the day’s lesson by discussing the key points.
• Mark the pupils’ work and provide feedback.
• Encourage pupils to practice more on their own to master the concepts.