Subtracting Three Digit Numbers

Subtracting three-digit numbers is similar to subtracting two-digit numbers, but this time we have to pay attention to the hundreds, tens, and ones.

For example, let's say we want to subtract 123 from 456. We will line them up just like before, but this time we will have to pay attention to the hundreds, tens, and ones.

  456

Now, we will start by subtracting the ones, which are the last digits of the numbers, 6 and 3. So 6 - 3 = 3. So we write 3 under the line.

  456

Next, we will move on to the tens, which are the middle digits of the numbers, 5 and 2. So 5 - 2 = 3. And we write 3 in front of the 3, like this:

  456

Finally, we will subtract the hundreds, which are the first digits of the numbers, 4 and 1. So 4 - 1 = 3. And we write 3 in front of the 33, like this:

  456

And that's it! We have subtracted the three-digit number 123 from 456 and got the answer 333.

Just like before, if the subtrahend (the number being subtracted) is larger than the minuend (the number from which we are subtracting), we have to borrow from the next digit to make subtraction possible.

For example, let's say we want to subtract 156 from 333. We will line them up just like before, but this time we will have to borrow from the next digit.

  333

Now, we will start by subtracting the ones, which are the last digits of the numbers, 3 and 6. So 3 - 6 = -3 (result is negative because 3 is smaller than 6) But we can't have negative numbers in subtraction, so we borrow 1 from the tens digit and add 10 to the units digit. So 3 becomes 13, and now we have 13-6 = 7. So we write 7 under the line.

  333

Next, we will move on to the tens, which are the middle digits of the numbers, 2 and 5. So 2 - 5 = -3 (result is negative because 3 is smaller than 5) But we can't have negative numbers in subtraction, so we borrow 1 from the hundreds digit and add 10 to the tens digit. So 2 becomes 12, and now we have 12-5 = 7. So we write 7 , like this:

   333

Finally, we will subtract the hundreds, which are the first digits of the numbers, 2 and 2. So 2 - 1 = 1 :

   333

And that's it! We have subtracted the three-digit number 156 from 333 and got the answer 177.