Subtraction of Large Numbers Calculator

This calculator subtracts two numbers of any length and shows the working using column subtraction with borrowing.

Step-by-step method

Step 1 (Set up): Write the two numbers in columns, aligned on the right (ones under ones). Put the − sign to the left of the bottom number, and draw a line underneath.

Step 2 (Repeat the column-subtraction cycle): Starting from the rightmost column, subtract column-by-column moving right to left. If you cannot subtract in a column, borrow from the column to the left, then subtract.

Example 1: 84 − 27

Step 1 (Set up): Write the two numbers in columns, aligned on the right (ones under ones). Put the − sign to the left of the bottom number, and draw a line underneath.

In this problem: In column subtraction, we put the larger number on top so each column works cleanly. Here, 84 is larger than or equal to 27, so we can subtract directly. Line up the digits and start from the ones column on the right.

Step 2 (Repeat the column-subtraction cycle): Starting from the rightmost column, subtract column-by-column moving right to left. If you cannot subtract in a column, borrow from the column to the left, then subtract.

In this problem: The top number has 2 digits, so we will subtract 2 columns: Step 2a, Step 2b, and so on—moving right to left.

Step 2a (Start with the rightmost column): Start with the rightmost column (ones). If you need to borrow, do that first, then subtract and write the digit.

In this problem: We need to borrow because 4 is smaller than 7.
Take 1 from 8, so it becomes 7. Add 10 to 4, so it becomes 14.
14 − 7 = 7. Write 7 under the ones column.

Step 2b (Move to the next column on the left): Move one column left and do the same steps again: borrow if needed, then subtract and write the digit.

In this problem: 7 − 2 = 5. Write 5 under the tens column.

Final answer: 84 − 27 = 57

Example 2: 1000 − 587

Step 1 (Set up): Write the two numbers in columns, aligned on the right (ones under ones). Put the − sign to the left of the bottom number, and draw a line underneath.

In this problem: In column subtraction, we put the larger number on top so each column works cleanly. Here, 1000 is larger than or equal to 587, so we can subtract directly. Line up the digits and start from the ones column on the right.

Step 2 (Repeat the column-subtraction cycle): Starting from the rightmost column, subtract column-by-column moving right to left. If you cannot subtract in a column, borrow from the column to the left, then subtract.

In this problem: The top number has 4 digits, so we will subtract 4 columns: Step 2a, Step 2b, and so on—moving right to left.

Step 2a (Start with the rightmost column): Start with the rightmost column (ones). If you need to borrow, do that first, then subtract and write the digit.

In this problem: We need to borrow because 0 is smaller than 7.
Take 1 from 1, so it becomes 0. Add 10 to 0, so it becomes 10.
Take 1 from 10, so it becomes 9. Add 10 to 0, so it becomes 10.
Take 1 from 10, so it becomes 9. Add 10 to 0, so it becomes 10.
10 − 7 = 3. Write 3 under the ones column.

Step 2b (Move to the next column on the left): Move one column left and do the same steps again: borrow if needed, then subtract and write the digit.

In this problem: 9 − 8 = 1. Write 1 under the tens column.

Step 2c (Move to the next column on the left): Move one column left and do the same steps again: borrow if needed, then subtract and write the digit.

In this problem: 9 − 5 = 4. Write 4 under the hundreds column.

Step 2d (Move to the next column on the left): Move one column left and do the same steps again: borrow if needed, then subtract and write the digit.

In this problem: 0 − 0 = 0. Write 0 under the thousands column.

Final answer: 1000 − 587 = 413