Addition and Subtraction – Basic Operations | JSS 1 Mathematics
Lesson Plan: Basic Operations – Addition and Subtraction
Subject: Mathematics
Class: JSS 1
Term: Second Term
Week: 6
Age: 10–12 years
Topic: Basic Operations
Sub-topic: Addition and Subtraction
Duration: 40 minutes
Behavioural Objectives
By the end of the lesson, students should be able to:
- Identify place values in numbers.
- Arrange numbers correctly for addition and subtraction.
- Add numbers correctly, ensuring proper alignment.
- Subtract numbers correctly, borrowing when necessary.
Keywords
- Addition
- Subtraction
- Place value
- Borrowing
- Carrying
Set Induction
The teacher asks:
- “What happens when you add two numbers?”
- “What do you do when you need to subtract a smaller number from a bigger one?”
- “Why is it important to align numbers properly before adding or subtracting?”
This introduces the topic and engages students.
Entry Behaviour
Students already know how to count and identify numbers up to thousands.
Learning Resources and Materials
- Flashcards with numbers
- Chart showing place values (units, tens, hundreds, thousands)
- Worksheets with addition and subtraction exercises
Building Background/Connection to Prior Knowledge
The teacher reminds students how numbers are structured in place value format and how to align them when performing basic operations.
Embedded Core Skills
- Logical reasoning
- Accuracy in calculation
- Problem-solving
Learning Materials
- Lagos State Scheme of Work
- Essential Mathematics for JSS 1
- New General Mathematics for Junior Secondary Schools
Instructional Materials
- Place value charts
- Whiteboard and marker for demonstrations
- Number flashcards
Content (Explanation in List Format)
1. Understanding Place Value in Addition and Subtraction
- Every number has place values: Units (U), Tens (T), Hundreds (H), Thousands (Th), etc.
- When performing addition or subtraction, numbers must be aligned properly according to place value.
2. Steps for Adding Numbers
- Step 1: Write the numbers one under the other, ensuring correct place value alignment.
- Step 2: Start adding from the rightmost digit (units).
- Step 3: If the sum of digits in a column is 10 or more, carry over to the next column.
- Step 4: Continue until all digits are added.
Example 1: Adding 345 and 678
- 5 + 8 = 13 (write 3, carry 1)
- 4 + 7 + 1 = 12 (write 2, carry 1)
- 3 + 6 + 1 = 10 (write 0, carry 1)
3. Steps for Subtracting Numbers
- Step 1: Write the numbers with proper alignment.
- Step 2: Start subtracting from the rightmost digit (units).
- Step 3: If the top digit is smaller than the bottom digit, borrow from the next column.
- Step 4: Continue until all digits are subtracted.
Example 2: Subtracting 457 from 823
- 3 – 7: Borrow 1 from 2 (making it 1), so 3 becomes 13. Now, 13 – 7 = 6.
- 1 – 5: Borrow 1 from 8 (making it 7), so 1 becomes 11. Now, 11 – 5 = 6.
- 7 – 4 = 3.
Thus, 823 – 457 = 366.
4. Checking Your Answers
- For Addition: Reverse the operation using subtraction.
- For Subtraction: Add the answer to the smaller number to check if you get the original larger number.
Example 3: Checking Addition
Now, subtract:
Since the result matches, the addition was correct.
Evaluation (10 Fill-in-the-Blank Questions with Options)
-
When adding, we start from the ______ place.
a) leftmost
b) middle
c) rightmost
d) thousands -
In subtraction, if the top digit is smaller than the bottom digit, we ______.
a) add 1
b) ignore it
c) borrow from the next column
d) multiply -
The sum of 234 and 567 is ______.
a) 801
b) 799
c) 771
d) 789 -
When subtracting 678 from 945, the answer is ______.
a) 257
b) 267
c) 277
d) 287 -
The process of carrying over in addition is used when the sum in a column is ______.
a) less than 10
b) equal to 10
c) 10 or more
d) more than 5 -
The number 843 subtracted from 1200 is ______.
a) 347
b) 357
c) 363
d) 375 -
To check subtraction, we use ______.
a) addition
b) division
c) multiplication
d) estimation -
In subtraction, borrowing means taking 1 from the next ______ place.
a) smaller
b) same
c) higher
d) equal -
456 + 239 equals ______.
a) 685
b) 695
c) 675
d) 715 -
The subtraction of 150 from 325 is ______.
a) 175
b) 185
c) 195
d) 200
Class Activity Discussion (10 FAQs with Answers)
-
Why do we align numbers before adding or subtracting?
- To ensure each place value is correctly positioned.
-
What should we do if the sum of a column is 10 or more?
- Carry over to the next column.
-
How do we check if our addition is correct?
- By subtracting the answer from one of the original numbers.
-
What happens when we need to subtract a bigger digit from a smaller digit?
- We borrow from the next place value.
-
Why is place value important?
- It helps in understanding how numbers are structured and aligned.
-
How do we check if our subtraction is correct?
- By adding the difference to the smaller number.
-
What is the result of adding 528 and 143?
- 671.
-
Why do we start addition from the rightmost digit?
- To handle carrying over properly.
-
If borrowing is needed in subtraction, what do we do?
- Take 1 from the next higher place value.
-
How can we practice addition and subtraction better?
- By solving different exercises and checking answers.