Doing arithmetic in binary
Enter two binary numbers (digits of only 0 and 1) and choose add, subtract, multiply, or divide. The tool converts both numbers to decimal to perform the calculation, then converts the result back to binary - useful for checking homework, debugging low-level code, or just getting a feel for how binary arithmetic lines up with the decimal numbers you already know.
Why binary matters beyond the classroom
Every value a computer stores is ultimately binary at the hardware level - working directly with binary numbers comes up in low-level programming (bitwise operations, flags, and masks), understanding networking concepts like subnet masks, and digital logic design, where operations happen directly on binary values rather than the decimal numbers most people think in day to day.
Why division truncates rather than showing a remainder
Division here returns a whole-number result, truncated rather than rounded - the same integer/floor division behavior most programming languages use by default. There's no binary-point or fractional output, so a division that doesn't divide evenly simply drops the remainder from the shown result.
Why negative results use a minus sign, not two's complement
If subtraction produces a negative number, the result is shown with a leading minus sign rather than in two's complement notation (the fixed-width representation computers actually use internally for negative binary numbers) - which keeps the result readable and directly comparable to the decimal value, at the cost of not reflecting exactly how a specific hardware register would represent that same negative number.