Long Addition Calculator

What is Long Addition?

Long addition is a systematic method for adding numbers by aligning them vertically by place value and adding column by column from right to left. When the sum of a column exceeds 9, the extra digit is carried over to the next column to the left. This method works for both whole numbers and decimal numbers and is a foundational skill in arithmetic. Master other arithmetic operations with our Long Subtraction Calculator with Regrouping and the Long Multiplication Calculator.

For example, adding 937, 129, and 2248 using long addition involves stacking the numbers so their place values align, then adding each column starting from the ones place. The ones column (7 + 9 + 8 = 24) gives 4 with a carry of 2 to the tens column. Continue this process through each column to arrive at the final sum of 3314.

How to Perform Long Addition

Follow these steps to add numbers using long addition:

• Align by place value: Write the numbers in a vertical column, aligning the digits by place value (ones, tens, hundreds, etc.). For decimal numbers, align the decimal points.
• Add from right to left: Start with the rightmost column (ones place). Add all the digits in that column together.
• Record and carry: Write the ones digit of the sum at the bottom of that column. If the sum is 10 or greater, carry the tens digit to the next column on the left.
• Continue through all columns: Repeat the process for each column, including any carried digits, until all columns have been added.

Adding Decimal Numbers with Long Addition

The process for adding decimal numbers with long addition is the same as for whole numbers, with the added step of aligning decimal points. When adding decimals like 37.5 + 129.44 + 48.123, align all the decimal points in the same column. If the numbers have different numbers of decimal places, pad the right side with zeros so they all have the same length. This ensures that place values are correctly aligned and the decimal point stays in the right position in the answer.