Class: Primary 1
Term: First Term
Week: 5
Age: 6 years
Duration: 45 minutes
Subject: Mathematics
Curriculum Theme: Number and Numeration
Previous Lesson: Place of Value, Recognition of 10 as a Group Use.
Topic: Addition
Subject Matter: Adding 2-digit numbers with sum less than 100 Without “Carrying Over”

Specific Objectives

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

Cognitive Domain:

Identify Tens (T) and Units (U) in 2-digit numbers.
Arrange 2-digit numbers correctly in place value columns for addition.
Perform addition of two 2-digit numbers without carrying over, where the sum is less than 100.

Affective Domain:

Show interest in solving addition problems.
Appreciate the importance of place value in addition.

Psychomotor Domain:

Accurately write down and solve 2-digit addition problems without carrying over.
Demonstrate the steps for adding 2-digit numbers using a place value chart.

Work cooperatively with peers to solve simple addition tasks.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum
State Unified Scheme of Work
New Oxford Primary Mathematics for Nigeria, Book 1
Chalkboard and chalk

Instructional Materials

The teacher will teach this lesson with the aid of:

A large place value chart (Tens and Units)
Number cards (0-9)
Counters or bottle tops
Chalk and chalkboard

Rationale for the Lesson

This lesson helps pupils understand how to combine quantities involving larger numbers, which is a fundamental skill for everyday calculations. Mastering this basic addition without carrying over builds a strong foundation for more complex mathematical operations and problem-solving in real-life situations.

Prerequisite/Previous Knowledge

Pupils can count numbers up to 50, identify single-digit numbers, and perform simple addition of single-digit numbers.

Lesson Content/Board Summary

Addition of 2-Digit Numbers Without Carrying Over

Understanding Place Value

Every digit in a number has a value based on its position. For 2-digit numbers, we have:

Tens (T): The digit on the left side, representing groups of ten.
Units (U): The digit on the right side, representing single items.

Example: In the number 27, ‘2’ is in the Tens place (meaning 20) and ‘7’ is in the Units place (meaning 7).

Adding 2-Digit Numbers (Without Carrying Over)

To add 2-digit numbers without carrying over, follow these steps:

Arrange the numbers vertically, ensuring the Units digits are aligned and the Tens digits are aligned.
Add the Units digits first.
Then, add the Tens digits.

Worked Example 1: Add 15 and 53

T U
1 5
+ 5 3
—–

Step 1: Arrange the numbers in their correct place values (Tens and Units).

Step 2: Add the Units digits: 5 + 3 = 8. Write ‘8’ under the Units column.

Step 3: Add the Tens digits: 1 + 5 = 6. Write ‘6’ under the Tens column.

Result: 15 + 53 = 68

Worked Example 2: Add 27 and 60

T U
2 7
+ 6 0
—–

Step 1: Arrange the numbers in their correct place values.

Step 2: Add the Units digits: 7 + 0 = 7. Write ‘7’ under the Units column.

Step 3: Add the Tens digits: 2 + 6 = 8. Write ‘8’ under the Tens column.

Result: 27 + 60 = 87

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils, reviews the previous lesson on adding single-digit numbers, and then introduces the topic of adding 2-digit numbers without carrying over.
Pupils’ Activity: Pupils respond to greetings, recall previous knowledge, and listen attentively to the new topic.
Learning Point: Pupils are prepared for the new lesson and connect it to prior knowledge.

Step 2: Explanation of Place Value

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher uses a place value chart to explain Tens (T) and Units (U) in 2-digit numbers, showing how to represent numbers like 15, 53, 27, and 60.
Pupils’ Activity: Pupils observe the place value chart and identify the Tens and Units digits of various 2-digit numbers.
Learning Point: Pupils understand the concept of place value for 2-digit numbers.

Step 3: Demonstration of Addition (Example 1)

Time: 10 minutes
Teaching Skill: Demonstration/Modelling
Teacher’s Activity: The teacher demonstrates how to add 15 and 53 on the board using the place value arrangement. The teacher emphasizes adding the Units digits first, then the Tens digits.
Pupils’ Activity: Pupils watch carefully as the teacher demonstrates the addition process.
Learning Point: Pupils observe the correct procedure for adding 2-digit numbers without carrying over.

Step 4: Guided Practice (Example 1)

Time: 5 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher writes another similar problem (e.g., 21 + 34) on the board and guides pupils to solve it step-by-step, encouraging them to participate in each stage.
Pupils’ Activity: Pupils participate in solving the problem, answering questions about which digits to add first and where to write the answers.
Learning Point: Pupils apply the learned steps with teacher guidance.

Step 5: Demonstration of Addition (Example 2)

Time: 8 minutes
Teaching Skill: Demonstration/Modelling
Teacher’s Activity: The teacher demonstrates the second example, adding 27 and 60, on the board, reinforcing the steps of adding Units first, then Tens.
Pupils’ Activity: Pupils pay attention to the second demonstration, noting the similar procedure.
Learning Point: Pupils reinforce their understanding by watching another example.

Step 6: Guided Practice (Example 2)

Time: 5 minutes
Teaching Skill: Independent Practice
Teacher’s Activity: The teacher provides a few more simple 2-digit addition problems without carrying over (e.g., 42 + 16, 30 + 58) for pupils to solve individually in their notebooks. The teacher walks around to provide support.
Pupils’ Activity: Pupils solve the given addition problems independently in their exercise books.
Learning Point: Pupils practice and build confidence in solving addition problems.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What does ‘T’ stand for in a place value chart?
What does ‘U’ stand for in a place value chart?
Solve: 32 + 45 = ?
Solve: 51 + 27 = ?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 5 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the main points of the lesson, reiterating the importance of place value and adding Units before Tens. The teacher then gives homework assignments related to adding 2-digit numbers without carrying over.
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their learning and prepare for further practice.

Home Task: Solve two new exercises on Addition. Show each step and check each answer.

Lesson Keywords

Addition – The process of combining two or more numbers to find their total.
Sum – The result obtained from adding two or more numbers.
Digits – The symbols used to write numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, 9).
Tens – A place value representing groups of ten.
Units – A place value representing single items (also called Ones).
Place Value – The value of a digit based on its position in a number.

Differentiation

For struggling learners, the teacher will use more concrete materials like counters and number cards to physically group and combine numbers. They will also be given fewer problems with smaller numbers. Advanced learners will be challenged with slightly larger 2-digit numbers (still without carrying over) or asked to create their own addition problems.

Note for teachers using this lesson plan

Emphasize the arrangement of numbers in their correct place value columns (Tens and Units) as this is foundational. Use visual aids like a large place value chart and concrete manipulatives to make the concept tangible for Primary 1 pupils. Ensure pupils understand the ‘Units first, then Tens’ rule to avoid confusion when carrying over is introduced later.