Long Addition Calculator
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Calculator Use
Add whole numbers and decimal numbers using long addition showing work. This calculator shows all the steps for adding numbers with long addition.
If all you need is a total of your numbers and do not need to see the long addition then use the Sum Calculator.
Separate values by commas or new lines. For example, when adding use either of the following formats:
Separated by commas
Separated by new lines
Whole
Numbers
Numbers
123, 456, 7890
123
456
7890
456
7890
Decimal
Numbers
Numbers
0.987, 65.4, 32.1
0.987
65.4
32.1
65.4
32.1
Do not use a comma as a thousands separator. Enter only positive numbers.
Adding Whole Numbers by Long Addition
Long addition is a process for adding numbers together.
- Stack your numbers and align the columns by place value.
- Add all numbers column by column from right to left.
- Record the sum in the answer space for each column.
- If the sum of any one column is greater than nine, carry the additional digits to the next highest column.
Example: Add by long addition 937 + 129 + 248
Long Addition Steps:
Stack and align the numbers by place value columns
Ones Place Value
7 + 9 + 8 = 24
Put the 4 in Ones place
Carry the 2 to Tens place
carry
2
9
3
7
1
2
9
+
2
4
8
4
Tens Place Value
2 + 3 + 2 + 4 = 11
Put the 1 in Tens place
Carry the 1 to Hundreds place
carry
1
2
9
3
7
1
2
9
+
2
4
8
1
4
Hundreds Place Value
1 + 9 + 1 + 2 = 13
Put the 3 in Hundreds place
Carry the 1 to Thousands place
carry
1
1
2
9
3
7
1
2
9
+
2
4
8
3
1
4
Thousands Place Value
1 = 1
Put the 1 in Thousands place
carry
1
1
2
9
3
7
1
2
9
+
2
4
8
1
3
1
4
Adding Decimal Numbers with Long Addition
The process for long addition with decimals is the same as the process of long addition of whole numbers with the added column for decimal places. Just as place values are stacked in the same column, all decimal points are stacked in the same column. If your individual numbers have different numbers of decimal places you can pad the right with zeros untill they all have the same number of decimal places.
For example, add 37.5 + 129.44 + 48.123
carry
1
2
1
3
7
.
5
0
0
1
2
9
.
4
4
0
+
4
8
.
1
2
3
2
1
5
.
0
6
3
Related Calculators
See the Long Subtraction with Regrouping Calculator to do long subtraction with regrouping or borrowing and see the work.