Lesson Notes By Weeks and Term v3 - Primary 2
Addition
Download the Lessonotes Mobile Nigeria 2025 app for faster lesson access on Android and iPhone.
Addition
Download the Lessonotes Mobile Nigeria 2025 app for faster lesson access on Android and iPhone.
Subject: General Mathematics
Class: Primary 2
Term: 1st Term
Week: 2
Theme: Basic Operations
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
Watch on YouTubeadd 2-digit numbers with out exchanging or renaming; add 3-digit numbers with out exchanging or renaming; add 2-digit numbers with exchanging or renaming; add 3 numbers taking two at a time.
Definition of Addition: Addition is the process of combining two or more numbers or quantities to find their total sum. The symbol for addition is `+` (plus). When numbers are added, the result is called the 'sum' or 'total'.
Place Value Review: Before embarking on addition, it is crucial to review place value (Units, Tens, Hundreds) as it underpins vertical addition, especially with exchanging.
Units (Ones): Represents single items (e.g., 1, 2, ..., 9).
Tens: Represents groups of ten (e.g., 10, 20, ..., 90). One ten is equal to ten units.
Hundreds: Represents groups of one hundred (e.g., 100, 200, ..., 900). One hundred is equal to ten tens.
Types of Addition Covered in this Lesson: A. Adding 2-Digit Numbers Without Exchanging (Renaming) This involves adding two numbers where the sum of the units column is 9 or less, and the sum of the tens column is also within single digits (or less than 10).
Method:
1. Arrange the numbers vertically, aligning the units digits and the tens digits.
2. Add the digits in the units column first.
3. Add the digits in the tens column.
Worked Example 1: Aminu has 23 kola nuts, and his friend Musa has 14 kola nuts. How many kola nuts do they have altogether?
Step 1: Arrange vertically. ``` T U 2 3 + 1 4 ----- ``` Step 2: Add the Units column (3 + 4 = 7). Write 7 under the Units column. ``` T U 2 3 + 1 4 ----- 7 ``` Step 3: Add the Tens column (2 + 1 = 3). Write 3 under the Tens column. ``` T U 2 3 + 1 4 ----- 3 7 ``` Answer: They have 37 kola nuts altogether. B. Adding 3-Digit Numbers Without Exchanging (Renaming) This involves adding two numbers where the sum of the units, tens, and hundreds columns are all 9 or less.
Method:
1. Arrange the numbers vertically, aligning the units, tens, and hundreds digits.
2. Add the digits in the units column first.
3. Add the digits in the tens column.
4. Add the digits in the hundreds column.
Worked Example 2: A school library has 125 storybooks and 213 textbooks. How many books are in the library in total?
Step 1: Arrange vertically. ``` H T U 1 2 5 + 2 1 3 ------- ``` Step 2: Add the Units column (5 + 3 = 8). Write 8 under the Units column. ``` H T U 1 2 5 + 2 1 3 ------- 8 ``` Step 3: Add the Tens column (2 + 1 = 3). Write 3 under the Tens column. ``` H T U 1 2 5 + 2 1 3 ------- 3 8 ``` Step 4: Add the Hundreds column (1 + 2 = 3). Write 3 under the Hundreds column. ``` H T U 1 2 5 + 2 1 3 ------- 3 3 8 ``` Answer: There are 338 books in total. C. Adding 2-Digit Numbers With Exchanging (Renaming / Carrying Over) This involves adding two numbers where the sum of the units column is 10 or more. The 'extra' ten from the units column must be carried over to the tens column.
Method:
1. Arrange the numbers vertically, aligning the units digits and the tens digits.
2. Add the digits in the units column.
3. If the sum is 10 or more, write down the unit digit of the sum under the units column and 'carry over' the tens digit of the sum to the tens column.
4. Add the digits in the tens column, remembering to include any carried-over digit.
Worked Example 3: Mama Nkechi sold 38 bags of garri on Monday and 27 bags on Tuesday. How many bags did she sell in total?
Step 1: Arrange vertically. ``` T U 3 8 + 2 7 ----- ``` Step 2: Add the Units column (8 + 7 = 15). Write 5 under the Units column and carry over 1 (ten) to the Tens column. ``` 1 T of the sum to the tens column.
4. Add the digits in the tens column, remembering to include any carried-over digit.
Worked Example 3: Mama Nkechi sold 38 bags of garri on Monday and 27 bags on Tuesday. How many bags did she sell in total?
Step 1: Arrange vertically. ``` T U 3 8 + 2 7 ----- ``` Step 2: Add the Units column (8 + 7 = 15). Write 5 under the Units column and carry over 1 (ten) to the Tens column. ``` 1 T U 3 8 + 2 7 ----- 5 ``` Step 3: Add the Tens column (3 + 2 = 5). Now add the carried-over 1 (ten) to this sum (5 + 1 = 6). Write 6 under the Tens column. ``` 1 T U 3 8 + 2 7 ----- 6 5 ``` Answer: Mama Nkechi sold 65 bags of garri in total. D. Adding Three Numbers (Taking Two at a Time) This approach simplifies adding multiple numbers by breaking it into successive two-number additions.
Method:
1. Add the first two numbers together.
2. Take the sum from step 1 and add the third number to it.
Worked Example 4: Three friends, Tunde, Aisha, and Chima, collected pebbles. Tunde collected 12, Aisha collected 15, and Chima collected
1
0. How many pebbles did they collect altogether?
Step 1: Add the first two numbers (Tunde's and Aisha's pebbles): 12 + 15. ``` T U 1 2 + 1 5 ----- 2 7 ``` Step 2: Add the result (27) to the third number (Chima's pebbles): 27 + 10. ``` T U 2 7 + 1 0 ----- 3 7 ``` Answer: They collected 37 pebbles altogether. --- Materials: Counting sticks, bottle tops, pebbles, or other concrete manipulatives. Place value charts (Ten-Frames, Hundreds charts) Flashcards with single and two-digit numbers. Whiteboard/chalkboard and markers/chalk. Exercise books/slates for students.
A. Introduction (10 minutes)
Review Place Value: The teacher revisits place value (Units, Tens, Hundreds) using concrete materials (e.g., showing 23 as 2 bundles of ten sticks and 3 single sticks). Students identify the tens and units in various two-digit numbers (e.g., 45, 70, 19).
Recall Basic Addition: The teacher conducts a quick mental maths activity involving single-digit addition (e.g., 5+3, 7+2, 9+1) to activate prior knowledge.
B. Development of Concepts (30 minutes)
Activity 1: Adding 2-digit Numbers Without Exchanging (10 minutes)
Teacher Demonstration: The teacher models adding 2-digit numbers without exchanging using a place value chart and concrete materials (e.g., 23 + 14). Explains aligning units and tens columns, then adding units first, then tens.
Guided Practice: Students use their manipulatives (e.g., bottle tops) to solve a similar problem in pairs (e.g., 31 + 25). The teacher circulates, offering support.
Board Work: Students demonstrate solving problems on the board, explaining their steps.
Activity 2: Adding 3-digit Numbers Without Exchanging (10 minutes)
Teacher Demonstration: The teacher models adding 3-digit numbers without exchanging (e.g., 125 + 213), emphasizing the alignment of hundreds, tens, and units columns.
Guided Practice: Students work individually or in pairs to solve a problem like 304 + 121 in their exercise books/slates, with the teacher providing direct supervision.
Activity 3: Adding 2-digit Numbers With Exchanging (10 minutes)
Teacher Demonstration (Crucial): The teacher models addition with exchanging using a place value chart and manipulatives. For example, when adding 27 + 15, explain that 7 units + 5 units = 12 units. Illustrate how 12 units become 1 ten and 2 units. Show carrying the 1 ten to the tens column.
Guided Practice: Students use manipulatives to work through a problem like 36 +
2
8. They should physically group 10 units to make 1 ten and move it to the tens column.
Board Work: Students practice on the board, articulating the "carry over" step clearly.
C. Application and Consolidation (15 minutes)
Activity 4: Adding Three Numbers (Taking Two at a Time)
Teacher Demonstration: The teacher demonstrates adding three numbers (e.g., 12 + 15 + 10) by first adding 12 + 15, then taking the sum and adding 10 to it.
Guided Practice: The teacher provides a word problem (e.g., "There are 18 boys, 10 girls, and 9 teachers at an event. How many people altogether?") and guides students to solve it by taking two numbers at a time.
Collaborative Solving: Students work in small groups to solve a similar problem, discussing their steps.
D. Wrap-up (5 minutes)
Q&A Session: The teacher addresses any remaining questions or areas of confusion.
Quick Review: The teacher verbally asks questions about key concepts, e.g., "When do we need to carry over?" "Which column do we add first?" --- Question 1 (Objective 1): Mr. Emeka has 42 oranges. His wife bought 35 more oranges. How many oranges do they have in total?
Solution: ``` T U 4 2 + 3 5 7 7 ``` Step 1: Add the Units: 2 + 5 =
7. Write 7 in the Units column.
Step 2: Add the Tens: 4 + 3 =
7. Write 7 in the Tens column.
Commentary: This problem reinforces adding 2-digit numbers without exchanging. The context of oranges is familiar in Nigeria.
Question 2 (Objective 2): A farmer planted 214 maize seeds in the first row and 135 maize seeds in the second row. How many maize seeds did he plant altogether?
Solution: ``` H T U 2 1 4 + 1 3 5 3 4 9 ``` Step 1: Add the Units: 4 + 5 =
9. Write 9 in the Units column.
Step 2: Add the Tens: 1 + 3 =
4. Write 4 in the Tens column.
Step 3: Add the Hundreds: 2 + 1 =
3. Write 3 in the Hundreds column.
Commentary: This problem helps students practice adding 3-digit numbers vertically without exchanging, using a farming context relevant to many Nigerian communities.
Question 3 (Objective 3): Chinedu sold 19 loaves of bread in the morning and 25 loaves in the afternoon. How many loaves did he sell altogether?
Solution: ``` 1 T U 1 9 + 2 5 4 4 ``` Step 1: Add the Units: 9 + 5 =
1
4. Write 4 in the Units column and carry over 1 to the Tens column.
Step 2: Add the Tens: 1 + 2 =
3. Add the carried-over 1: 3 + 1 =
4. Write 4 in the Tens column.
Commentary: This question focuses on addition of 2-digit numbers requiring exchanging, a crucial skill. The context of selling bread is common in Nigerian markets.
Question 4 (Objective 4): At a local festival, there were 20 drummers, 15 dancers, and 12 singers. How many performers were there in total?
Solution: Step 1: Add the first two numbers (drummers and dancers): ``` T U 2 0 + 1 5 3 5 ``` Step 2: Add the sum from Step 1 to the third number (singers): ``` T U 3 5 + 1 2 4 7 ```
Commentary: This problem reinforces adding three numbers by taking two at a time, within a culturally relevant context of a festival. ---
Market Shopping and Budgeting: Students can apply addition to calculate the total cost of items bought from a local market. For instance, if Mama Chika buys yams for ₦250 and palm oil for ₦120, students can add these amounts to find the total expenditure (₦250 + ₦120 = ₦370). This helps them understand budgeting and money management in a Nigerian context.
Community Census/Statistics: Addition can be used to count people or resources in a community. For example, if a village has 315 children, 280 adults, and 50 elders, students can add these numbers to find the total population in different age groups. This relates to understanding demographic data and community planning.
Agriculture and Harvest: In farming communities, addition is essential for keeping track of produce. A farmer might need to add the number of bags of maize harvested from different plots (e.g., 55 bags from plot A and 38 bags from plot B) to know the total harvest (55 + 38 = 93 bags). This is crucial for planning sales or storage. ---