Learning 2-digit minus 1-digit subtraction without borrowing technique

📚 Introduction to 2-Digit Minus 1-Digit Subtraction (No Borrowing)

Subtraction is a fundamental arithmetic operation that involves finding the difference between two numbers. When subtracting a 1-digit number from a 2-digit number without borrowing, we ensure that the ones digit of the 2-digit number is greater than or equal to the 1-digit number we are subtracting. This allows us to perform the subtraction directly without needing to borrow from the tens place.

📜 Historical Context

The concept of subtraction has ancient roots, dating back to early civilizations that used counting systems. The development of place value systems, like the one we use today, greatly simplified arithmetic operations, including subtraction. The method of subtracting without borrowing is a simplified approach often taught to introduce young learners to subtraction, building a solid foundation before introducing more complex borrowing techniques.

🔑 Key Principles

• ➕ Understanding Place Value: Know the difference between the tens and ones places in a 2-digit number. For example, in 25, 2 is in the tens place (representing 20) and 5 is in the ones place.
• ✅ Ensuring Feasibility: Before subtracting, make sure the ones digit of the 2-digit number is greater than or equal to the 1-digit number. If it is, you can subtract directly.
• ➖ Subtracting the Ones: Subtract the 1-digit number from the ones digit of the 2-digit number. Keep the tens digit the same.

📝 Step-by-Step Guide

1. Write the Problem: Align the numbers properly, with the 2-digit number on top and the 1-digit number below, ensuring the ones digits are aligned.
2. Check the Ones Digits: Verify that the ones digit of the top number is greater than or equal to the bottom number.
3. Subtract: Subtract the ones digits.
4. Write the Result: Write the difference in the ones place and carry over the tens digit from the top number directly to the answer.

🧮 Example Problems

Example 1: $47 - 2 = ?$

1. Write the problem:

	4	7
-		2

2. Check the ones digits: 7 is greater than 2, so we can proceed.
3. Subtract: $7 - 2 = 5$
4. Write the result: The tens digit is 4, and the ones digit is 5, so the answer is 45.

Therefore, $47 - 2 = 45$

Example 2: $98 - 6 = ?$

1. Write the problem:

	9	8
-		6

2. Check the ones digits: 8 is greater than 6, so we can proceed.
3. Subtract: $8 - 6 = 2$
4. Write the result: The tens digit is 9, and the ones digit is 2, so the answer is 92.

Therefore, $98 - 6 = 92$

💡 Tips and Tricks

• 🧮 Use Manipulatives: Use blocks or counters to physically represent the numbers and perform the subtraction.
• ✍️ Practice Regularly: Consistent practice reinforces the concept and builds confidence.
• 📖 Break It Down: If the numbers seem large, break down the problem into smaller, more manageable steps.

📝 Practice Quiz

1. $29 - 3 = ?$
2. $56 - 4 = ?$
3. $87 - 5 = ?$
4. $35 - 2 = ?$
5. $68 - 6 = ?$

✅ Solutions

1. $29 - 3 = 26$
2. $56 - 4 = 52$
3. $87 - 5 = 82$
4. $35 - 2 = 33$
5. $68 - 6 = 62$

निष्कर्ष

Mastering 2-digit minus 1-digit subtraction without borrowing is a crucial step in building a strong foundation in arithmetic. By understanding place value and following a simple subtraction process, learners can confidently solve these problems. Keep practicing, and you'll become a subtraction pro in no time!