Practice converting between binary and decimal numbers. Type your answer and beat the timer to level up!
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Binary is the fundamental language of computers. While we use the decimal system (base 10) with digits 0 through 9 in everyday life, computers operate using the binary system (base 2), which uses only two digits: 0 and 1. Every piece of data on your computer — text, images, videos, and software — is ultimately represented as sequences of these two digits, called bits. The word "bit" is short for "binary digit," and it is the smallest unit of data in computing.
To convert a binary number to decimal, assign each digit a positional value based on powers of 2, starting from the rightmost digit at position 0. Multiply each binary digit by its corresponding power of 2, then add all the results together.
Adding them up: 8 + 4 + 0 + 1 = 13. So binary 1101 equals decimal 13.
To convert a decimal number to binary, repeatedly divide the number by 2 and record the remainder at each step. Continue dividing the quotient by 2 until you reach 0. Then read the remainders from bottom to top — that sequence is the binary representation.
Reading remainders from bottom to top: 11001. So decimal 25 equals binary 11001.
Here is a quick reference table for the most common binary-to-decimal conversions. Memorizing these values will help you convert numbers faster during the game.
| Decimal | Binary | Decimal | Binary |
|---|---|---|---|
| 0 | 0000 | 8 | 1000 |
| 1 | 0001 | 9 | 1001 |
| 2 | 0010 | 10 | 1010 |
| 3 | 0011 | 11 | 1011 |
| 4 | 0100 | 12 | 1100 |
| 5 | 0101 | 13 | 1101 |
| 6 | 0110 | 14 | 1110 |
| 7 | 0111 | 15 | 1111 |
Understanding binary is essential for anyone interested in computer science, programming, or information technology. Binary is the foundation of how processors execute instructions, how memory stores data, and how networks transmit information. Learning to convert between binary and decimal builds your number sense, strengthens logical thinking, and gives you a deeper understanding of how the digital world works beneath the surface. Whether you are a student, a developer, or simply curious, practicing binary conversions is a valuable and rewarding skill.
2Bit is a free, interactive binary conversion game designed to make learning fun and effective. You are presented with a number and must convert it between binary and decimal before the timer runs out. Each correct answer earns points and advances you to the next level, where the numbers get larger and more challenging. Build a streak of consecutive correct answers to prove your mastery. Choose from three game modes: Mixed (random direction), BIN → DEC (binary to decimal only), or DEC → BIN (decimal to binary only). The game is available in English and Italian.