You've learned about working with three-digit column subtraction. Now we'll learn about working with four-digit columns. This is also very simple. Just remember what you already know about regrouping (borrowing) once or twice with three-digit place values. You will need to do the same with four-digit problems. In no time, you will be able to subtract four-digit numbers easily.
Subtract 9,548 minus 1,980.
How many times do you think you need to regroup in this problem? If you said twice, you are correct. You don't need to regroup anything when solving the ones place (ones column) because you can already solve 8 minus 0 (8 - 0). You know the difference (answer) equals 8.
In the tens place, you need to subtract 4 minus 8 (4 - 8). You will have to regroup. You need to regroup from the hundreds place. (You will sometimes see the terms "tens column" and "hundreds column" used.) First, add the 1 you regrouped from the hundreds place to the 4 in the tens place: 10 + 4 = 14. Then cross out the 5 in the hundreds place and write 4.
The 4 becomes 14, and you can subtract 14 minus 8. What is it? The difference is 6.
The digit in the hundreds place is now 4. You need to subtract 4 minus 9 (4 - 9). Regroup the digits again. Let the 4 in the hundreds place regroup one from the 9 in the thousands place (thousands column).
The 4 in the hundreds place becomes 14, and the 9 in the thousands place becomes 8. Try subtracting the numbers. Can you work with all of them now?
Take a look at the following column subtraction:
Solving four-digit column subtraction problems is the same as any other subtraction problem. Just take it one step at a time.
