Subtraction With Regrouping
2026-02-28 23:47 Diff
https://brightchamps.com/en-us/math/numbers/subtraction-with-regrouping

Subtraction of 4-digit numbers with regrouping is done in the same way as with 1-digit, 2-digit, and 3-digit numbers. Since this involves 4 digits, the place values are thousands, hundreds, tens, and ones. Let’s look at an example: Subtract 4529 from 7384.


Step 1: Arrange the numbers by place value
Write the numbers vertically, with digits aligned according to place value:

  7 3 8 4
- 4 5 2 9
-------------
-------------
 

Start subtracting from the ones place: Compare 4 (top) and 9 (bottom). Since 4 < 9, we need to borrow.

Borrowing 1 ten from the tens place (which has 8) converts 4 → 14, and reduces the tens digit from 8 to 7.

Now subtract the ones digits: 14 − 9 = 5


Step 2: Subtract the tens place
After borrowing, the tens digits are 7 (top) and 2 (bottom). Since 7  ≥  2, no borrowing is needed here.

Subtract: 7 − 2 = 5


Step 3: Subtract the hundreds place
Compare hundreds digits: 3 (top) and 5 (bottom). Since 3 < 5, we must borrow.


Borrow 1 thousand from the thousands place (which has 7), reducing it to 6 and adding 10 hundreds to the hundreds place:


3 + 10 = 13
3 → 13


Now subtract hundreds digits: 13 − 5 = 8


Step 4: Subtract the thousands place
After borrowing, the thousands digits are 6 (top) and 4 (bottom).
Subtract: 6 − 4 = 2


So,

Ones: 14 − 9 = 5
Tens: 7 − 2 = 5
Hundreds: 13 − 5 = 8
Thousands: 6 − 4 = 2
 

Final answer: 7384 − 4529 = 2855