Long Subtraction Calculator with Regrouping
Do long subtraction with regrouping or borrowing. Enter whole numbers or decimal numbers to find the difference. This calculator finds the answer using long subtraction with regrouping and shows the work step by step.
Steps for Long Subtraction with Regrouping
Long subtraction lets you find the difference between two numbers.
- Stack your numbers with the larger one on top and the smaller one on the bottom
- Align your numbers so that the place values line up in columns (ones, tens, hundreds, etc.)
- If you have decimal points they should also line up in a column
- Working from right to left, subtract the bottom number from the top number
- Put the answer at the bottom of each column
- If the bottom number is larger than the top number you need to regroup, borrowing value from the number in the column to the left. See the continued steps below.
How to do Regrouping in Subtraction
Regrouping in subtraction is taking value from one number and giving it to another number. Just as you carry digits to another number in long addition, you borrow digits from another number in long subtraction.
- In a column, if the top number is smaller than the bottom number, look at the next number to the left in the top row
- Cross out that number and write the value of that number minus 1 in its place
- Cross out the top number from your original column and write the value of that number plus 10 in its place: You are regrouping or borrowing from the next higher place value into the lower place value
- Proceed with subtracting the bottom number from the new, larger top number
- Put the answer at the bottom of the column
- If you encounter a 0 while regrouping, just continue to the left until you find a non-zero number. Regroup (borrow) 10 from each column until you're back at the column you're working on.
- Continue the long subtraction until you have completed subtraction on all columns
Try our Long Addition Calculator to add numbers by long addition and see the work.