What is Subtraction With Borrowing? | Simple Explanation for Class 2

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What is Subtraction With Borrowing (Regrouping)?

Grade Level:

Class 2

Maths, Computing

Definition

What is it?

Subtraction with Borrowing (also called Regrouping) is a method we use when the digit we are subtracting from (the top digit) is smaller than the digit we need to subtract (the bottom digit) in the same place value column. It involves 'borrowing' or 'regrouping' from the digit in the next higher place value column to make the subtraction possible.

Simple Example

Quick Example

Imagine you have 32 laddoos and your friend wants 15 laddoos. You can't directly give 5 laddoos from the 2 laddoos you have in the ones place. So, you 'borrow' from the tens place. You break one group of ten laddoos into ten single laddoos, adding them to your 2 single laddoos, making 12 laddoos. Now you can easily give 5 laddoos.

Worked Example

Step-by-Step

Let's subtract 27 from 53.

Step 1: Write the numbers one below the other, aligning the ones place and tens place.
53
- 27
-----

Step 2: Start with the ones place. We need to subtract 7 from 3. Since 3 is smaller than 7, we cannot subtract directly.

Step 3: 'Borrow' from the tens place. The 5 in the tens place becomes 4 (because we took one 'ten'). The 3 in the ones place becomes 13 (because we added 10 ones to it).
4 13
5 3
- 2 7
-----

Step 4: Now subtract the ones place: 13 - 7 = 6.
4 13
5 3
- 2 7
-----
6

Step 5: Move to the tens place. Subtract 2 from 4 (remember the 5 became 4).
4 13
5 3
- 2 7
-----
2 6

Answer: 53 - 27 = 26.

Why It Matters

Understanding subtraction with borrowing is a fundamental skill in mathematics, essential for daily calculations and more complex problems. It's crucial for careers in finance like an accountant managing budgets, or in engineering where precise measurements and calculations are needed, and even in computing for algorithms involving numerical operations.

Common Mistakes

MISTAKE: Forgetting to reduce the digit in the 'borrowed from' column after borrowing. | CORRECTION: Always remember to subtract 1 from the digit in the next higher place value after you 'borrow' from it.

MISTAKE: Subtracting the smaller digit from the larger digit, regardless of its position. For example, in 33 - 17, doing 7-3 in the ones place. | CORRECTION: Always subtract the bottom digit from the top digit. If the top digit is smaller, you must borrow.

MISTAKE: Not understanding that 'borrowing a 1' from the tens place means adding 10 to the ones place. | CORRECTION: When you borrow 1 from the tens place, it means you're taking one group of ten, which is equal to ten ones. So, add 10 to the digit in the ones place.

Practice Questions

Try It Yourself

QUESTION: Subtract 18 from 45. | ANSWER: 27

QUESTION: A bus started with 62 passengers. At the next stop, 29 passengers got off. How many passengers are left on the bus? | ANSWER: 33 passengers

QUESTION: Your dad had Rs. 750 in his wallet. He bought groceries worth Rs. 385. How much money does he have left? | ANSWER: Rs. 365

MCQ

Quick Quiz

What is the result of 71 - 34?

The Correct Answer Is:

To solve 71 - 34, you borrow from the tens place for the ones column (11 - 4 = 7). Then, in the tens column, you subtract 3 from the remaining 6 (6 - 3 = 3), giving 37. Options B, C, D show incorrect borrowing or subtraction.

Real World Connection

In the Real World

Imagine you're tracking scores in a cricket match. If Team A scored 235 runs and Team B scored 187 runs, to find the difference in scores, you'd use subtraction with borrowing. Or, if you have 500 MB of mobile data and use 175 MB, calculating the remaining data involves this concept, which apps like MyJio or Airtel Thanks use internally.

Key Vocabulary

Key Terms

SUBTRACTION: Taking one number away from another | BORROWING: The process of taking value from a higher place value column to help subtract in a lower one | REGROUPING: Another term for borrowing, meaning to rearrange values within place values | PLACE VALUE: The value of a digit based on its position in a number (e.g., ones, tens, hundreds) | DIFFERENCE: The result of subtraction

What's Next

What to Learn Next

Once you're comfortable with subtraction with borrowing, you can move on to 'Subtraction with Borrowing Across Zeros' and 'Multi-digit Subtraction'. These concepts will build on your understanding of place value and borrowing to solve even bigger problems.