Add two numbers and keep a short history of your calculations.
Last updated: June 2026 | By Patchworkr Team
Enter valid real numbers (decimal or scientific notation).
Addition combines two numbers into one total. The result tells you how much you have when the numbers are put together.
The commutative property means the order of the numbers does not change the sum. 12 + 10 and 10 + 12 both equal 22, so you can rearrange terms when that makes the calculation easier.
Zero is the identity for addition, so adding 0 does not change a number.
This calculator accepts real numbers, so you can add positive numbers, negative numbers, and decimals.
When the signs are different, the result depends on which number has the larger magnitude. For example, -8 + 3 = -5 because the negative value is farther from zero. If the magnitudes are equal, such as -5 + 5, the result is zero.
Decimal addition follows the same rules as whole-number addition. The decimal places line up, the place values are added separately, and the final total is combined from those partial sums.
The result is shown as a clean decimal value, and the calculator keeps a short history if you want to revisit previous sums.
Does this accept decimals?
Yes. It accepts decimals and scientific notation.
Can I add negative numbers?
Yes. Negative numbers are fully supported.
What if I leave a field blank?
Blank input is treated as invalid so the calculator does not guess.
Why does the result format to 8 digits?
It keeps the display readable while preserving precision.