Subtraction of 3-Digit Numbers (Grade 2)
Subtraction of 3-digit numbers means taking away one big number from another big number. In Class 2, you learn to subtract numbers that have hundreds, tens, and ones.
You already know how to subtract 2-digit numbers. Subtracting 3-digit numbers works the same way — you just have one extra column on the left for hundreds.
We always start subtracting from the ones place (the rightmost column), then move to the tens place, and finally to the hundreds place. Writing the numbers one below the other in a column helps keep the digits lined up properly.
This skill is very useful in real life. For example, if a shop has 456 pencils and sells 123, you need 3-digit subtraction to find how many pencils are left.
What is Subtraction of 3-Digit Numbers - Class 2 Maths (Subtraction)?
Subtraction of 3-digit numbers means finding the difference between two numbers that have up to three digits (numbers from 100 to 999). We line up the numbers by their place values and subtract each column one at a time.
There are two types of 3-digit subtraction:
- Without borrowing (regrouping): Every digit on top is bigger than or equal to the digit below it. This is simpler.
- With borrowing (regrouping): Sometimes a digit on top is smaller than the digit below it. Then we need to borrow from the next place value. In Class 2, we mostly practise subtraction without borrowing first.
How to write the subtraction:
| H (Hundreds) | T (Tens) | O (Ones) | |
|---|---|---|---|
| Big number | 4 | 5 | 6 |
| − Small number | 1 | 2 | 3 |
| = Answer | 3 | 3 | 3 |
Subtraction of 3-Digit Numbers (Grade 2) Formula
Step 1: Subtract Ones → Step 2: Subtract Tens → Step 3: Subtract Hundreds
Types and Properties
Types of 3-digit subtraction problems you will see:
- 3-digit minus 3-digit: 867 − 432 = 435
- 3-digit minus 2-digit: 745 − 23 = 722 (treat the 2-digit number as having 0 hundreds)
- 3-digit minus round numbers: 500 − 200 = 300 (subtracting hundreds only)
- Word problems: Real-life stories about books, stickers, mangoes, and more
Solved Examples
Example 1: Simple 3-Digit Subtraction (No Borrowing)
Question: Solve 867 − 432
Think: Write the numbers in a place value chart and subtract each column from right to left.
| H | T | O | |
|---|---|---|---|
| − | 8 | 6 | 7 |
| 4 | 3 | 2 | |
| = | 4 | 3 | 5 |
- Ones: 7 − 2 = 5
- Tens: 6 − 3 = 3
- Hundreds: 8 − 4 = 4
Answer: 867 − 432 = 435
Example 2: Subtraction with Zeros
Question: Solve 590 − 260
Think: Zeros in the ones place make it easy — just write 0 in the ones place of the answer.
- Ones: 0 − 0 = 0
- Tens: 9 − 6 = 3
- Hundreds: 5 − 2 = 3
Answer: 590 − 260 = 330
Example 3: Word Problem — Library Books
Question: The school library has 375 books. 142 books are sent to another school. How many books are left?
Think:
- Total books = 375
- Books sent away = 142
- We subtract to find what is left: 375 − 142
- Ones: 5 − 2 = 3
- Tens: 7 − 4 = 3
- Hundreds: 3 − 1 = 2
Answer: 233 books are left in the library.
Example 4: Word Problem — Mangoes in a Shop
Question: A fruit shop had 486 mangoes in the morning. Aman bought 153 mangoes. How many mangoes are left in the shop?
Think:
- Total mangoes = 486
- Mangoes sold = 153
- Mangoes left = 486 − 153
- Ones: 6 − 3 = 3
- Tens: 8 − 5 = 3
- Hundreds: 4 − 1 = 3
Answer: The shop has 333 mangoes left.
Example 5: Subtracting a 2-Digit Number from a 3-Digit Number
Question: Solve 745 − 23
Think: When subtracting a 2-digit number from a 3-digit number, write the 2-digit number below the tens and ones columns. The hundreds column of the smaller number is 0.
- Ones: 5 − 3 = 2
- Tens: 4 − 2 = 2
- Hundreds: 7 − 0 = 7
Answer: 745 − 23 = 722
Example 6: Word Problem — Stickers Collection
Question: Priya has 568 stickers in her collection. She gives 245 stickers to her friend Meera. How many stickers does Priya have now?
Think:
- Priya starts with 568 stickers
- She gives away 245 stickers
- 568 − 245
- Ones: 8 − 5 = 3
- Tens: 6 − 4 = 2
- Hundreds: 5 − 2 = 3
Answer: Priya has 323 stickers left in her collection.
Example 7: Subtraction Using a Place Value Chart
Question: Solve 699 − 456 using a place value chart.
Think:
| Hundreds | Tens | Ones | |
|---|---|---|---|
| − | 6 | 9 | 9 |
| 4 | 5 | 6 | |
| = | 2 | 4 | 3 |
- Ones: 9 − 6 = 3
- Tens: 9 − 5 = 4
- Hundreds: 6 − 4 = 2
Answer: 699 − 456 = 243
Example 8: Subtracting Hundreds Only
Question: Solve 800 − 500
Think:
- Both numbers have 0 in tens and ones places
- We only need to subtract hundreds: 8 − 5 = 3
Answer: 800 − 500 = 300
Real-World Applications
Where do we use 3-digit subtraction?
- Shopping: Finding how much money is left after buying something. If you have ₹500 and spend ₹275, you have ₹225 left.
- School: Finding how many students are absent. If 350 students are enrolled and 312 came today, then 38 are absent.
- Counting stock: A shop finding how many items are left after selling some.
- Distance: Finding how much farther you need to travel. If the total journey is 450 km and you have done 210 km, you have 240 km left.
Key Points to Remember
- Always start subtracting from the ones place (right side) and move left.
- Write the numbers one below the other. Line up hundreds under hundreds, tens under tens, ones under ones.
- If the top digit is bigger than or equal to the bottom digit, subtract normally.
- Check your answer by adding: answer + smaller number should give the bigger number. For example, 867 − 432 = 435. Check: 435 + 432 = 867. Correct!
- Use a place value chart (H, T, O) to keep digits in the correct columns.
- When subtracting a 2-digit number from a 3-digit number, write 0 in the hundreds place of the smaller number.
Practice Problems
- Solve: 897 − 453
- Solve: 675 − 342
- Ria has 546 beads. She uses 213 beads to make a necklace. How many beads are left?
- Solve: 789 − 456
- A school has 998 pencils. 465 pencils are given to students. How many pencils remain?
- Solve: 500 − 300
Frequently Asked Questions
Q1. What is subtraction of 3-digit numbers?
It means finding the difference between two numbers that have hundreds, tens, and ones. We subtract each place value starting from the ones column, just like with 2-digit numbers but with an extra hundreds column.
Q2. Where do we start subtracting 3-digit numbers?
Always start from the ones place (the rightmost column). Then move to the tens column. Finally, subtract the hundreds column.
Q3. What does borrowing mean in subtraction?
Borrowing (also called regrouping) is needed when the top digit is smaller than the bottom digit. You take 1 ten from the tens place to make 10 extra ones. In Class 2, most problems do not need borrowing.
Q4. How can I check my subtraction answer?
Add the answer to the smaller number. If you get the bigger number back, your subtraction is correct. For example, 867 − 432 = 435. Check: 435 + 432 = 867. Since we get 867 back, the answer is correct.
Q5. Can we subtract a 2-digit number from a 3-digit number?
Yes. Write the 2-digit number below the ones and tens columns. The hundreds column of the smaller number becomes 0. Then subtract normally.
Q6. What happens when we subtract a number from itself?
The answer is always 0. For example, 365 − 365 = 0. Any number minus itself is zero.
Q7. Why do we need to line up the digits in columns?
Each column represents a different value — ones, tens, and hundreds. If the digits are not lined up correctly, we will subtract the wrong values and get a wrong answer.
Q8. What is the difference between 3-digit subtraction with and without borrowing?
Without borrowing: every top digit is bigger, so you subtract directly. With borrowing: when a top digit is smaller, you borrow 1 from the next column. For example, in 432 − 218, the ones: 2 is less than 8, so you borrow from the tens place.
