Lesson Notes By Weeks and Term v3 - Primary 1
Addition I
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Addition I
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Subject: General Mathematics
Class: Primary 1
Term: 1st Term
Week: 6
Theme: Basic Operations
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Watch on YouTubeadd two whole numbers from 1 to 3 with sum less than 5; add two or three whole numbers from 1 to 8 with sum not up to 10; add two or three numbers from 0 to 9 with sum not greater than 18; add 2-digit whole numbers with sum not greater than 40 with out exchanging or renaming; cross check numeracy in addition is readable.
=
1
5. Example 3 (Nigerian Context): At a naming ceremony, they used 9 small gourds of palm oil and 7 small gourds of groundnut oil. How many gourds of oil were used in total? Start from
9. Count on 7: 10, 11, 12, 13, 14, 15,
1
6. Answer: 16 gourds. (9 + 7 = 16).
Objective 4: Adding 2-digit whole numbers with sum not greater than 40 without exchanging or renaming (no carrying over).
Concept: Introduction to columnar addition (place value). Emphasize adding units (ones) first, then tens. No digit in the units column should sum to 10 or more.
Place Value: Explain that a 2-digit number like 15 has 1 ten and 5 units (ones).
Example 1: 12 + 13 = ?
Step 1: Arrange vertically (columnar addition): ``` T U 1 2 + 1 3 ----- ``` Step 2: Add the Units (ones) column: 2 units + 3 units = 5 units. Write '5' under the units column. ``` T U 1 2 + 1 3 ----- 5 ``` Step 3: Add the Tens column: 1 ten + 1 ten = 2 tens. Write '2' under the tens column. ``` T U 1 2 + 1 3 ----- 2 5 ``` So, 12 + 13 =
2
5. Example 2 (Nigerian Context): A farmer harvested 20 tubers of yam in the morning and 15 tubers in the afternoon. How many tubers of yam did he harvest in total?
Arrange: ``` T U 2 0 + 1 5 ----- ``` Add Units: 0 + 5 = 5 Add Tens: 2 + 1 = 3 Result: ``` T U 2 0 + 1 5 ----- 3 5 ``` Answer: 35 tubers of yam.
Objective 5: Cross-checking numeracy in addition is readable.
Concept: Emphasize the importance of neat handwriting, clear digit formation, and checking answers for accuracy.
Readability: Digits should be clearly distinguishable (e.g., '1' should not look like '7'). Numbers should be aligned properly in columns, especially for 2-digit addition.
Cross-checking: Re-count/Re-add: Encourage students to add the numbers again, perhaps in a different order (if adding two numbers), or re-count the objects.
Peer Check: Students can exchange their work with a partner to verify readability and correctness. 2.1 Definition of Addition: Addition is the process of combining two or more numbers or quantities to find their total or sum. It answers the question, "How many in all?" or "How many altogether?" 2.2 Symbols Used in Addition: '+' (Plus sign): This symbol means "add" or "combine with." For example, 2 + 3 means "2 combined with 3." '=' (Equals sign): This symbol means "is equal to" or "gives a total of." For example, 2 + 3 = 5 means "2 combined with 3 is equal to 5." 2.3 Understanding Whole Numbers: Whole numbers are 0, 1, 2, 3, 4, 5, and so on. They are the counting numbers including zero. 2.4 Strategies for Addition (Concrete and Pictorial): Counting All: Students count every item from two separate groups after they are combined.
Counting On: Students start counting from the larger number and count forward the number of items in the second group.
Using Manipulatives: Concrete objects like fingers, toes, pebbles, bottle tops, seeds (e.g., _achi_ or _ogiri_ seeds), counting sticks, or beads are essential tools.
Number Line: A visual representation where numbers are placed at equal intervals. Addition involves moving to the right on the number line. 2.5 Step-by-Step Addition
Examples: Objective 1: Adding two whole numbers from 1 to 3 with sum less than
5. Concept: Simple combinations of very small numbers.
Example 1: 2 + 1 = ?
Method 1 (Using objects): Gather 2 bottle tops. Then gather 1 more bottle top.
Count all the bottle tops: 1, 2,
3. So, 2 + 1 =
3. Method 2 (Counting on): Start from
2. Count on 1 more:
3. So, 2 + 1 =
3. Example 2 (Nigerian Context): A child has 3 oranges. His mother gives him 1 more orange. How many oranges does he have now? Start with 3 oranges. Add 1 more orange.
Count: 1, 2, 3,
4. Answer: 4 oranges. (3 + 1 = 4).
Objective 2: Adding two or three whole numbers from 1 to 8 with sum not up to
1
0. Concept: Slightly larger combinations, still manageable with fingers or few objects.
Example 1: 4 + 3 = ?
Method (Counting on): Start from
4. Count on 3 more: 5, 6,
7. So, 4 + 3 =
7. Example 2: 2 + 5 + 1 = ?
Method (Using objects/Counting on): Take 2 pebbles. Take 5 pebbles. Take 1 pebble. Combine them all.
Count all: 1, 2, 3, 4, 5, 6, 7,
8. So, 2 + 5 + 1 =
8. Example 3 (Nigerian Context): A boy caught 6 fish. His sister caught 3 fish. How many fish did they catch altogether? Start with
6. Count on 3: 7, 8,
9. Answer: 9 fish. (6 + 3 = 9).
Objective 3: Adding two or three numbers from 0 to 9 with sum not greater than
1
8. Concept: Involves numbers up to 9, sums can go slightly beyond 10, requiring more counting or mental strategies.
Example 1: 7 + 8 = ?
Method (Counting on): Start from the larger number,
8. Count on 7 more: 9, 10, 11, 12, 13, 14,
1
5. So, 7 + 8 =
1
5. Example 2: 5 + 6 + 4 = ?
Method (Counting on in stages): First, add 5 +
6. Start from 6, count on 5: 7, 8, 9, 10,
1
1. Now add 11 +
4. Start from 11, count on 4: 12, 13, 14,
1
5. So, 5 + 6 + 4 =
1
5. Example 3 (Nigerian Context): At a naming ceremony, they used 9 small gourds of palm oil and 7 small gourds of groundnut oil. How many gourds of oil were used in total? Start from
9. Count on 7: 10, 11, 12, 13, 14, 15,
1
6. Answer: 16 gourds. (9 + 7 = 16).
Objective 4: Adding 2-digit whole numbers with sum not greater than 40 without exchanging or renaming (no carrying over). * Concept: Introduction to columnar addition (place value). Emphasize adding units (ones) first, then tens. No 3.1 Teacher Activities: Introduction (Recall): Begin by recalling previous knowledge of counting and number recognition (1-20). Ask students to count various objects in the classroom.
Concept Introduction: Introduce the concept of "putting together" or "combining" quantities using real objects like pencils, books, stones, or bottle tops. Demonstrate with simple scenarios (e.g., "I have 2 pencils, and I picked up 1 more. How many do I have now?"). Demonstration (P.O. 1 & 2): Use fingers, counting beads, or a number line to demonstrate addition of small numbers (e.g., 2+1, 4+3, 2+5+1). Model "counting on" strategy. Demonstration (P.O. 3): Demonstrate addition of slightly larger single-digit numbers (e.g., 7+8, 5+6+4) using a larger number line or by grouping manipulatives. Demonstration (P.O. 4): Introduce 2-digit addition without exchanging. Use place value charts (Tens and Units columns) if available, or simply draw columns on the board. Explicitly show how to align numbers vertically (Units under Units, Tens under Tens) and how to add the units column first, then the tens column. Model several examples clearly on the board. Promoting Readability (P.O. 5): Consistently emphasize neatness in writing numbers and aligning them. Demonstrate how to write numbers clearly and how incorrect alignment can lead to errors. Show how to re-check answers by re-adding.
Guided Practice: Facilitate whole-class and small-group guided practice sessions using concrete materials.
Monitoring and Support: Circulate among students during activities, offering individual support, corrections, and encouragement.
Summarizing: At the end of each segment, summarize the key points covered. 3.2 Student Activities: Manipulative Play: Students will use concrete objects (e.g., bottle tops, pebbles, fingers) to act out simple addition problems.
Counting On: Students will practice counting on from a given number to find the sum of two numbers.
Number Line Use: Students will use individual number lines (or a classroom number line) to solve addition problems.
Worksheet/Whiteboard Practice: Students will solve addition problems on worksheets, notebooks, or individual whiteboards, focusing on correct answers and clear writing.
Group Activities: "Addition Chain": Students add a number to the previous sum in a circle. "Object Hunt & Add": Groups collect a specified number of objects and add them together.
Columnar Addition Practice: Students will practice arranging and adding 2-digit numbers in columns in their notebooks or on prepared activity sheets.
Peer Checking: Students will exchange notebooks with a partner to check for readability and simple errors, under teacher supervision.
Verbal Participation: Students will answer questions orally and explain their addition strategies. The teacher will guide students through these examples, encouraging them to use manipulatives or counting on strategies. Question 1 (Aligned with P.O. 1): Grace has 2 mangoes. Her brother gives her 1 more mango. How many mangoes does Grace have in total?
Solution: Start with 2 mangoes. Add 1 more mango.
Count all the mangoes: 1, 2,
3. So, 2 + 1 =
3. Commentary: This is a simple combination problem, easily solved by counting all or counting on. Reinforces basic addition concept. Question 2 (Aligned with P.O. 2): A farmer planted 3 okra seeds, then 4 more, and later 2 more. How many okra seeds did he plant altogether?
Solution: First, add 3 +
4. Start from 4, count on 3: 5, 6, 7. (So far, 7 seeds). Now, add 7 +
2. Start from 7, count on 2: 8,
9. So, 3 + 4 + 2 =
9. Commentary: This problem involves adding three single-digit numbers, with a sum less than
1
0. It encourages step-by-step addition. Question 3 (Aligned with P.O. 3): During a school market day, Emeka sold 6 handmade beads. His friend, Chika, sold 7 handmade beads. How many beads did they sell altogether?
Solution: To find 6 + 7: Start from the larger number,
7. Count on 6 more: 8, 9, 10, 11, 12,
1
3. So, 6 + 7 =
1
3. Commentary: This problem involves a sum greater than 10 but not exceeding 18, requiring more counting on skill or manipulatives. Question 4 (Aligned with P.O. 4): Papa bought a loaf of bread for ₦10 and some groundnuts for ₦
2
5. How much did Papa spend in total?
Solution: Arrange the numbers in columns: ``` T U 1 0 (Bread) + 2 5 (Groundnuts) ``` Add the Units column: 0 + 5 = 5. ``` T U 1 0 + 2 5 5 ``` Add the Tens column: 1 + 2 = 3. ``` T U 1 0 + 2 5 3 5 ``` So, ₦10 + ₦25 = ₦
3
5. Commentary: This introduces 2-digit addition without carrying, emphasizing correct column alignment and adding units before tens. The Naira symbol adds local context. Question 5 (Aligned with P.O. 5 - integrated): A teacher gave out 4 exercise books on Monday and 5 exercise books on Tuesday. How many books were given out in total? Write your answer clearly and neatly.
Solution: 4 + 5 =
9. The student should write the number '9' clearly and legibly.
Commentary: This question integrates the addition skill with the need for good penmanship. The teacher should physically check the student's writing for clarity and readability.
Market Transactions (Economy): Students can relate addition to buying and selling in local markets. For example, if a child buys 5 garden eggs and 3 tomatoes, they can add to find the total number of items bought. This helps them understand simple budgeting and transaction accuracy.
Community Projects/Events (Community): In Nigerian communities, people often contribute items or help in specific numbers. For instance, if 10 men and 8 women volunteer for a community clean-up, addition helps to find the total number of volunteers. This fosters an understanding of collective effort and statistics. Home Chores and Family Counting (Culture/Daily Life): Children can apply addition by counting family members (e.g., 2 parents + 3 children = 5 family members), or by adding up items related to chores (e.g., 6 plates washed in the morning + 5 plates washed in the evening). This connects mathematics to their immediate environment and cultural practices like family size and division of labour.