Grade 4 → Addition and Subtraction ↓
Subtraction of Large Numbers
Subtraction is a basic arithmetic operation that helps us find the difference between two numbers. When we subtract a smaller number from a larger number, we are essentially finding out how many more digits the larger number has than the smaller one. In this detailed guide, we will explore how subtraction works when dealing with large numbers and ensure that you have a solid foundation to solve such problems with ease.
What is subtraction?
Subtraction is the process of subtracting one number from another. If you have 10 apples and you give away 3, you can find out how many apples you have left by subtracting 3 from 10. The number sentence or equation is:
10 - 3 = 7
The negative is 10, the subtraction is 3, and the difference is 7.
Visualization of subtraction
Let's visualize subtraction using the example of large numbers. Consider subtraction:
543 - 278
As we solve the problem, we need to subtract each digit of the subtracted from each digit of the subtracted, starting from the rightmost digit or ones place.
Step-by-step subtraction process
Step 1: Subtract the units
Look at the digit in the units place:
3 - 8
Since 3 is less than 8, we need to subtract 1 from the tens place.
Step 2: Borrow from the tens
When we subtract 4 from the tens place of 543, it becomes 3, and the 3 in the units place becomes 13:
So now the subtraction is done:
13 - 8 = 5
Write 5 in the units place of the answer.
Step 3: Subtract the tens
After borrowing, the tens digits are:
3 - 7
Again, 3 is less than 7, so we now have to borrow from the hundreds place.
Step 4: Borrow from hundreds
When we subtract the digit in the hundreds place, 5 becomes 4, and the 3 in the tens place becomes 13:
Now the subtraction will be like this:
13 - 7 = 6
Write 6 in the tens place of the answer.
Step 5: Subtract the hundreds
Finally, subtract the digits in the hundreds place:
4 - 2
This is equivalent to:
4 - 2 = 2
Write 2 in the hundreds place of the answer.
Full answer
So, the difference is 265. As you can see, subtracting large numbers can be accomplished by following several clear steps. Let's try another example:
Example 2: Subtracting 7562 from 8438
Install it vertically initially:
8438 - 7562 ------
Subtract one
Starting from the units place:
8 - 2 = 6
Write 6 in the units place below the line.
Subtracting tens
Going to the tens place:
3 - 6
Since 3 is less than 6, borrow 1 from the hundreds place:
4 becomes 3, and the 3 in the tens place becomes 13:
13 - 6 = 7
Write a 7 under the line in the tens place.
Subtracting hundreds
In the hundreds place:
3 - 5
Since 3 is smaller than 5, borrow 1 from the thousands place:
The digit of 8 became 7, and the digit of 3 in the hundreds place became 13:
13 - 5 = 8
Write 8 in the hundreds place below the line.
Subtracting thousands
Finally, in the thousands place:
7 - 7 = 0
Write a 0 below the line in the thousands place. So, the complete solution looks like this:
8438 - 7562 ------ 876
Practice problems
Here are some problems for you to practice. With all this knowledge, who wouldn't want to practice subtraction?
Try these:
1. 6549 - 2384 = ? 2. 9713 - 4865 = ? 3. 8230 - 7459 = ? 4. 4596 - 1728 = ? 5. 10984 - 7689 = ?
Work through each problem using the steps above, and check your answers when you're finished. Remember, practice is key to mastering subtraction!
Conclusion
Subtracting large numbers may seem challenging at first, but by understanding the process of borrowing and subtracting digit by digit, you'll find it much easier. Using examples, visual aids, and following clear steps will guide you to confidently solve any subtraction problem. Keep practicing, and you'll soon become an expert at subtraction!