Long Subtraction Calculator with Regrouping

What is Long Subtraction with Regrouping?

Long subtraction with regrouping, also known as subtraction with borrowing, is a method for subtracting one number from another when some digits in the top number are smaller than the corresponding digits in the bottom number. Instead of getting a negative result in a column, we borrow 1 from the next higher place value, which adds 10 to the current column. This process is repeated across columns as needed until all subtractions are complete. Practice other arithmetic operations with our Long Addition Calculator and the Long Multiplication Calculator.

For example, when subtracting 147 from 245, the ones column has 5 minus 7. Since 5 is smaller than 7, we borrow 1 from the tens column (reducing 4 to 3) and add 10 to the ones column (making 5 into 15). Then 15 minus 7 equals 8. Continue this process for each column to get the final result of 98.

How to Perform Long Subtraction with Regrouping

Follow these steps for long subtraction with regrouping:

• Stack the numbers: Write the larger number on top and the smaller number below it, aligning the digits by place value. For decimals, align the decimal points.
• Work from right to left: Start with the rightmost column (ones place). Subtract the bottom digit from the top digit.
• Regroup when needed: If the top digit is smaller than the bottom digit, borrow 1 from the digit in the next column to the left. Cross out that digit, reduce it by 1, and add 10 to the current column's digit.
• Write the result: Put the difference at the bottom of each column. Continue through all columns from right to left.

How Regrouping Works in Subtraction

Regrouping (borrowing) in subtraction is the process of taking value from one place value column and giving it to the column to the right. When a top digit is smaller than the bottom digit, you look at the digit in the next column to the left. If that digit is non-zero, you decrease it by 1 and add 10 to the current column's digit. If the next column has a 0, you continue moving left until you find a non-zero digit, borrowing 10 from each column along the way. This process ensures the subtraction can be completed correctly in each column.