Addition Of Two 3-Digit Numbers Basic 2 Mathematics Lesson Note

Learning Objectives

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

• Count and identify numbers from 1-530 (focus on 510-530)
• Write numbers 510-530 and 1-530 in numerals and words
• Add two 3-digit numbers without exchanging or renaming
• Solve real-life problems involving 3-digit addition
• Understand place value in 3-digit addition

Lesson Content

Day 1: Counting to 530

New Number Range:

• Practice counting from 1-530
• Focus on numbers 510-530: 510, 511, 512… 530
• Smooth counting through: 519, 520, 521…
• Learn to read: “five hundred and thirty”

Number Writing:

• Practice writing 510, 515, 520, 525, 530
• Write in both numerals and words
• Emphasize neat, clear formation

Day 2: Understanding 3-Digit Addition

What are 3-Digit Numbers?

• Numbers from 100 to 999
• Have hundreds, tens, and units places
• Examples: 234, 567, 801

Setting Up 3-Digit Addition:

 H T U

  2 3 4

+ 1 4 2

——-

  3 7 6

No Exchanging Means:

• Units column sum ≤ 9
• Tens column sum ≤ 9
• Hundreds column sum ≤ 9

Day 3-4: Adding 3-Digit Numbers

Step-by-Step Method:

1. Write numbers in columns (H-T-U)
2. Add units column first
3. Add tens column next
4. Add hundreds column last
5. Write your answer

Example 1: 234 + 142

 H T U

  2 3 4

+ 1 4 2

——-

  3 7 6

• Units: 4 + 2 = 6
• Tens: 3 + 4 = 7
• Hundreds: 2 + 1 = 3
• Answer: 376

Example 2: 321 + 156

 H T U

  3 2 1

+ 1 5 6

——-

  4 7 7

• Units: 1 + 6 = 7
• Tens: 2 + 5 = 7
• Hundreds: 3 + 1 = 4
• Answer: 477

Day 5: Real-Life Applications

Shopping Examples: “A shop sold items worth 234 naira in the morning and 145 naira in the evening. How much did they sell altogether?” 234 + 145 = 379 naira

School Examples: “School A has 312 pupils and School B has 275 pupils. How many pupils are there in both schools?” 312 + 275 = 587 pupils

Examples in Class

Place Value in 3-Digit Numbers:

• 456 = 4 hundreds + 5 tens + 6 units
• 203 = 2 hundreds + 0 tens + 3 units
• 518 = 5 hundreds + 1 ten + 8 units

Addition Examples:

Example 1: 123 + 245

 1 2 3

+ 2 4 5

——-

  3 6 8

Example 2: 312 + 126

 3 1 2

+ 1 2 6

——-

  4 3 8

Real-Life Examples:

Library Books: “The main library has 245 books and the branch library has 132 books. How many books do both libraries have together?” 245 + 132 = 377 books

Fruit Market: “A trader bought 134 oranges and 253 apples. How many fruits did he buy altogether?” 134 + 253 = 387 fruits

Exercises

Exercise 1: Number Practice

Write these numbers:

1. Five hundred and fifteen = ___
2. Five hundred and twenty-eight = ___
3. 519 in words = ___
4. 526 in words = ___

Count and fill missing numbers: 5. 525, 526, ___, 528, ___, 530

Exercise 2: Place Value Understanding

Break down these numbers:

1. 345 = ___ hundreds + ___ tens + ___ units
2. 502 = ___ hundreds + ___ tens + ___ units
3. 427 = ___ hundreds + ___ tens + ___ units

Exercise 3: 3-Digit Addition (No Exchanging)

Solve these problems:

1. 234 2. 145 3. 312 4. 256

• 123 + 231 + 146 + 142

1. 421 6. 325 7. 134 8. 267

• 137 + 163 + 254 + 121

Exercise 4: Horizontal Addition

1. 123 + 245 = ___
2. 234 + 134 = ___
3. 156 + 232 = ___
4. 321 + 167 = ___

Exercise 5: Check Your Work

Add and check if the sum has exchanging (it shouldn’t):

1. 234 + 123 = ___ (Units: 4+3=7 ✓, Tens: 3+2=5 ✓, Hundreds: 2+1=3 ✓)
2. 145 + 142 = ___
3. 312 + 156 = ___

Exercise 6: Real-Life Problems

1. A school has 234 boys and 145 girls. How many pupils are there altogether? 
2. In January, a shop made 267 naira profit. In February, they made 132 naira profit. What was their total profit for both months? 
3. Farm A produced 156 bags of rice and Farm B produced 231 bags of rice. How many bags of rice did both farms produce together? 
4. A library bought 145 storybooks and 123 textbooks. How many books did they buy in total? 

Exercise 7: Shopping Problems

1. Mom bought groceries for 178 naira and clothes for 221 naira. How much did she spend altogether? 
2. A toy shop sold toys worth 234 naira on Monday and 165 naira on Tuesday. What was the total sales for both days? 
3. Dad saved 267 naira in his first piggy bank and 132 naira in his second piggy bank. How much money did he save in total? 

Fun Activities

• 3-Digit Building: Use base-10 blocks to build and add 3-digit numbers
• Market Addition: Role-play adding up costs of multiple items
• Number Race: Quick 3-digit addition competitions
• Real Shopping: Practice with actual price tags and receipts

Homework

• Practice 8 three-digit addition problems daily
• Find 3-digit numbers around home and add them
• Help parents add up shopping costs
• Practice writing numbers 510-530 neatly

Assessment

• Can the child count to 530 accurately?
• Do they understand place value in 3-digit numbers?
• Can they add two 3-digit numbers without exchanging?
• Can they identify when no exchanging is needed?
• Can they apply 3-digit addition to real-life problems?

Teaching Notes

Important Reminders:

• Ensure students line up digits properly in columns
• Check that sums in each column don’t exceed 9
• Use base-10 blocks or place value charts for visual support