Subtraction Of Two 2-Digit Numbers (Without Renaming) Basic 2 Mathematics Lesson Note

Learning Objectives

By the end of this week, pupils should be able to:

• Count and identify numbers from 1-430
• Write numbers 410-430 and 1-430 in numerals and words
• Identify subtraction terms and the subtraction sign (-)
• Subtract 2-digit numbers without exchanging/renaming
• Create and solve subtraction stories
• Solve real-life subtraction problems

Lesson Content

Day 1: Counting to 430

New Number Range:

• Practice counting from 1-430
• Focus on numbers 410-430: 410, 411, 412… 430
• Learn to read and write these numbers clearly
• Practice both forward and backward counting

Day 2: Understanding Subtraction

The Subtraction Sign (-): The – sign means “subtract” or “take away”

Other Words for Subtraction:

• Take away
• Minus
• Left
• Difference
• Remaining
• How many more/less

Example: “What is the difference between 45 and 23?” means “What is 45 – 23?”

Day 3-4: Subtracting 2-Digit Numbers (No Renaming)

What is “No Renaming”? This means we can subtract each column without borrowing. The top number in each column is bigger than or equal to the bottom number.

Method:

1. Write the numbers one under the other
2. Subtract the units column first
3. Subtract the tens column next
4. Write your answer

Example 1:

 48

– 23

—-

  25

• Units: 8 – 3 = 5
• Tens: 4 – 2 = 2
• Answer: 25

Example 2:

 67

– 34

—-

  33

• Units: 7 – 4 = 3
• Tens: 6 – 3 = 3
• Answer: 33

Day 5: Subtraction Stories and Real-Life Problems

Creating Subtraction Stories:

• “Sarah has 45 sweets. She eats 12 sweets. How many sweets are left?”
• 45 – 12 = 33 sweets left

Solving Real-Life Problems:

• Shopping: “Dad had 58 naira. He spent 26 naira. How much money is left?”
• School: “There were 47 pupils in the hall. 25 pupils went out. How many pupils remained?”

Examples in Class

Step-by-Step Examples:

Example 1: 56 – 32

Step 1: Write numbers    Step 2: Subtract units    Step 3: Subtract tens

   56                        56                        56

 – 32                      – 32                      – 32

 —-                      —-                      —-

                             4                         24

Units: 6 – 2 = 4, Tens: 5 – 3 = 2, Answer: 24

Example 2: 79 – 46

  79

 – 46

 —-

   33

Units: 9 – 6 = 3, Tens: 7 – 4 = 3, Answer: 33

Real-Life Examples:

At the Shop: “Mom had 65 naira. She bought bread for 23 naira. How much money does she have left?” 65 – 23 = 42 naira

In the Classroom: “There were 58 pencils in the box. The teacher gave out 36 pencils. How many pencils are left in the box?” 58 – 36 = 22 pencils

Exercises

Exercise 1: Number Practice

Write these numbers:

1. Four hundred and fifteen = ___
2. Four hundred and twenty-eight = ___
3. 419 in words = ___
4. 425 in words = ___

Exercise 2: Subtraction Terms

What do these words mean in math?

1. Take away = ___
2. Difference = ___
3. Remaining = ___
4. Minus = ___

Exercise 3: Simple Subtraction

Solve these subtraction problems:

1. 58 2. 67 3. 79 4. 86

• 25 – 43 – 35 – 52

1. 95 6. 48 7. 73 8. 64

• 42 – 26 – 51 – 33

Exercise 4: Horizontal Subtraction

Solve these:

1. 67 – 34 = ___
2. 58 – 27 = ___
3. 79 – 45 = ___
4. 86 – 52 = ___

Exercise 5: Subtraction Stories

Solve these story problems:

1. John has 48 marbles. He gives 25 marbles to his friend. How many marbles does John have left? 
2. A tree has 67 mangoes. 34 mangoes fall down. How many mangoes are still on the tree? 
3. There were 85 pupils in the assembly. 43 pupils went back to class. How many pupils remained in the assembly? 

Exercise 6: Real-Life Problems

1. A shop has 76 bottles of water. If 45 bottles are sold, how many bottles are left? 
2. Mary has 59 naira. She spends 27 naira on sweets. How much money does she have remaining? 
3. A bus has 68 seats. If 36 seats are occupied, how many seats are empty? 

Exercise 7: Mixed Practice

1. Which is bigger: 67 – 23 or 45 – 12?
2. Find the difference between 58 and 26.
3. Take away 35 from 74.
4. How many more is 67 than 34?

Fun Activities

• Subtraction Detective: Find the missing numbers in subtraction problems
• Story Theater: Act out subtraction stories
• Real-Life Subtraction: Practice with classroom supplies

Homework

• Practice 10 subtraction problems daily
• Create 3 subtraction stories using things at home
• Help parents subtract while shopping (change calculations)

Assessment

• Can the child count to 430 accurately?
• Do they understand subtraction terms and the – sign?
• Can they subtract two 2-digit numbers without renaming correctly?
• Can they create and solve subtraction stories?
• Can they apply subtraction to solve real-life problems?
• Do they understand that subtraction is the opposite of addition?