In mathematics and digital electronics, a binary number is a number expressed in the binary numeral system or base-2 numeral system which represents numeric values using two different symbols: typically 0 (zero) and 1 (one). So "0" and "1" have the same meanings in binary and ordinary decimal notation. But "10" in binary means 2 in decimal, "100" means 2x2 (=4) in decimal. Continuing on, "1000" means 2x2x2 (=8) and "10000" means 2x2x2x2 (=16).

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