Free Long Addition Calculator

This long addition calculator adds whole numbers or decimals and shows the full working — column by column, with every carry — exactly the way you'd solve it by hand. Enter as many numbers as you like, one per line or separated by commas.

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Long Addition Calculator

Separate values by commas or new lines. Positive whole numbers or decimals only — no thousands-separator commas within a number.

Input Format Examples

TypeSeparated by CommasSeparated by New Lines
Whole Numbers123, 456, 7890123
456
7890
Decimal Numbers0.987, 65.4, 32.10.987
65.4
32.1

Result

Solution:

Share This Calculation

Opening this link fills in your numbers and shows this result automatically.

Enter your numbers and the sum, worked out step by step, will appear here.

How Long Addition Works

Long addition is just the formal name for the column-by-column method most of us learned in school — stack the numbers up, line up the place values, and add each column from right to left, carrying over into the next column whenever a column adds up to 10 or more.

The Steps

  1. Stack the numbers so matching place values line up in the same column.
  2. Add the digits in the rightmost column first.
  3. Write down the ones digit of that sum, and carry any tens digit into the next column to the left.
  4. Repeat for every column, including any carried digit, until you reach the leftmost column.

Worked Example: 937 + 129 + 2248

Ones: 7 + 9 + 8 = 24 → write 4, carry 2
Tens: 2(carry) + 3 + 2 + 4 = 11 → write 1, carry 1
Hundreds: 1(carry) + 9 + 1 + 2 = 13 → write 3, carry 1
Thousands: 1(carry) + 2 = 3
Total: 3,314

Adding Decimals With Long Addition

Decimals work exactly the same way, as long as you line up the decimal points in one column too. If your numbers have a different number of decimal places, pad the shorter ones with trailing zeros first so every column has a digit to add — this calculator does that part for you automatically.

37.500 + 129.440 + 48.123 = 215.063

Using the Share, Print and Copy Options

  • Share: After you calculate, a ready-made link appears with your exact numbers baked in. Send it to anyone and their page opens already filled in with your result showing.
  • Print: Prints just your numbers and the worked solution — no ads, menus or surrounding page clutter.
  • Copy: Copies a plain-text version of the answer straight to your clipboard, ready to paste anywhere.

Frequently Asked Questions (FAQs)

Seeing every carry laid out column by column is exactly how the method is taught and graded in school, so it's useful for checking homework or understanding where a hand-worked answer went wrong, not just getting the final total.

Yes, enter as many numbers as you need, one per line or separated by commas, and the calculator will stack and add all of them together in one pass.

Commas are used here to separate different numbers from each other, so a comma inside a number like "1,000" would be read as two separate numbers, 1 and 000. Just type it as 1000 instead.

No. The link only encodes the exact numbers you typed in, so anyone opening it sees the same calculation you did, nothing more.

No, this calculator only accepts positive numbers, since long addition as a method assumes every value is being added, not subtracted.

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