Subtraction 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 1-550 (focus on 530-550)
• Write numbers 530-550 and 1-550 in numerals and words
• Subtract two 2-digit numbers without regrouping
• Subtract two 3-digit numbers without regrouping
• Relate subtraction to real-life problems (shopping, change calculation)
• Solve practical problems involving money and change

Lesson Content

Day 1: Counting to 550

New Number Range:

• Practice counting from 1-550
• Focus on numbers 530-550: 530, 531, 532… 550
• Master reading: “five hundred and thirty”, “five hundred and fifty”
• Practice both forward and backward counting

Number Writing:

• Write 530, 535, 540, 545, 550
• Practice in both numerals and words
• Emphasize clear, neat formation

Day 2: Review 2-Digit Subtraction (No Regrouping)

When No Regrouping is Needed:

• Top digit in each column ≥ bottom digit
• We can subtract directly

Examples:

 67    89    45

– 34  – 56  – 23

—-  —-  —-

  33    33    22

Day 3-4: 3-Digit Subtraction (No Regrouping)

Setting Up 3-Digit Subtraction:

 H T U

  4 6 8

– 2 3 5

——-

  2 3 3

Step-by-Step Method:

1. Write numbers in columns (H-T-U)
2. Check: Can we subtract each column? (No borrowing needed)
3. Subtract units first
4. Subtract tens next
5. Subtract hundreds last

Example 1: 468 – 235

 H T U

  4 6 8

– 2 3 5

——-

  2 3 3

• Units: 8 – 5 = 3
• Tens: 6 – 3 = 3
• Hundreds: 4 – 2 = 2
• Answer: 233

Example 2: 579 – 346

 H T U

  5 7 9

– 3 4 6

——-

  2 3 3

• Units: 9 – 6 = 3
• Tens: 7 – 4 = 3
• Hundreds: 5 – 3 = 2
• Answer: 233

Day 5: Real-Life Applications

Shopping and Change Problems: “A shopkeeper had 465 items. He sold 243 items. How many items are left?” 465 – 243 = 222 items

Money Problems: “Dad had 389 naira. He spent 156 naira. How much money does he have left?” 389 – 156 = 233 naira

Examples in Class

Place Value in Subtraction:

When subtracting 567 – 234:

• Hundreds: 5 – 2 = 3
• Tens: 6 – 3 = 3
• Units: 7 – 4 = 3
• Answer: 333

Real-Life Examples:

At the Shop: “A shop had 478 bottles of soft drinks. 245 bottles were sold during the week. How many bottles are left?” 478 – 245 = 233 bottles

School Supplies: “A school ordered 567 exercise books. They distributed 234 books to students. How many books are left in the store?” 567 – 234 = 333 books

Change Calculation:

“Mom paid 500 naira for items worth 278 naira. How much change should she receive?” 500 – 278 = 222 naira

Exercises

Exercise 1: Number Practice

Write these numbers:

1. Five hundred and thirty-five = ___
2. Five hundred and forty-eight = ___
3. 542 in words = ___
4. 537 in words = ___

Exercise 2: Check for Regrouping Need

Look at these problems. Can we subtract without regrouping? (YES/NO)

1. 678 – 234 = ___
2. 567 – 345 = ___
3. 489 – 267 = ___
4. 578 – 456 = ___

Exercise 3: 2-Digit Subtraction Review

Solve these (no regrouping):

1. 89 2. 67 3. 78 4. 96

• 45 – 34 – 56 – 23

Exercise 4: 3-Digit Subtraction (No Regrouping)

Solve these problems:

1. 567 2. 489 3. 678 4. 789

• 234 – 156 – 345 – 456

1. 598 6. 467 7. 689 8. 578

• 267 – 234 – 456 – 345

Exercise 5: Horizontal Subtraction

1. 456 – 234 = ___
2. 578 – 345 = ___
3. 689 – 456 = ___
4. 467 – 123 = ___

Exercise 6: Real-Life Problems

1. A farmer had 456 yams. He sold 234 yams at the market. How many yams does he have left? 
2. A shop had 567 exercise books. 234 books were sold to students. How many books remain in the shop? 
3. Mary collected 489 bottle tops. She gave 156 bottle tops to her friend. How many bottle tops does she have now? 
4. A school has 678 pupils. 345 pupils went on an excursion. How many pupils remained in school? 

Exercise 7: Money and Change Problems

1. Mom had 500 naira. She spent 267 naira at the market. How much money does she have left? 
2. Dad bought fuel for 378 naira from 500 naira. How much change did he receive? 
3. A toy costs 456 naira. If you pay 500 naira, how much change will you get? 
4. John saved 489 naira. He spent 156 naira on books. How much money does he have remaining? 

Exercise 8: Mixed Practice

1. Which is bigger: 567 – 234 or 456 – 123?
2. Find the difference between 489 and 267.
3. From 578, take away 345.
4. How much less is 234 than 567?

Fun Activities

• 3-Digit Subtraction Race: Solve problems quickly and accurately
• Market Day: Practice calculating change with 3-digit numbers
• Number Detective: Find which problems can be solved without regrouping
• Real Shopping: Use actual price tags for practice

Homework

• Practice 8 three-digit subtraction problems daily
• Help parents calculate change when shopping
• Find examples of 3-digit numbers at home and practice subtraction
• Write numbers 530-550 neatly

Assessment

• Can the child count to 550 accurately?
• Do they understand 3-digit place value?
• Can they subtract 3-digit numbers without regrouping?
• Can they identify when no regrouping is needed?
• Can they solve real-life problems involving money and change?
• Do they line up digits correctly in columns?

Teaching Notes

Key Points to Emphasize:

• Proper alignment of digits in columns
• Working from right to left (units, tens, hundreds)
• Checking that no regrouping is needed before starting
• Connecting to real money situations for practical understanding
• Using place value language throughout