Mon Prof Augmenté
Binary Switch Row
Age 16 · Technology
A row of four switches controls four blocks. Raised switches light their blocks gold, and the red-framed switch marks the negative place value in a four-bit two’s complement number.
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Age 16: open this week
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In the picture
- Red-framed switch: the sign position, worth −8 in a four-bit two’s complement number.
- Cube with a minus sign: the negative place value attached to the sign position.
- Gold-lit cube under a raised lever: a place value that is included.
- Dim grey cube under a lowered lever: a place value that is left out.
- Smallest cube: the 1s place in the four-bit group.
Examples
- A bank app stores a negative balance using two’s complement in its binary data.
- A game character’s position below zero is stored as a two’s complement integer.
Key takeaways
- In unsigned binary, place values are powers of two: 1, 2, 4, 8, and so on from right to left.
- In two’s complement, the leftmost bit has a negative weight, so 1111 means −1 in four bits.
Quiz: Binary Switch Row (Age 16)
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In unsigned binary, what are the place values from right to left?
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In a four-bit two’s complement number, what value does the leftmost bit have?
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In four-bit two’s complement, what decimal value does 1111 represent?
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