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Signed eight-bit values

Set 2 of 8 · 32 worked questions. Predict your result before expanding the solution.

These worked traces are meant to build fluency through controlled variation. If several answers feel identical, try the next difficult value and look for the point where a carry, sign, branch, or selected memory address changes the outcome.

Foundations · Problem 0033

Interpret 00100000 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100000 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 32.
  6. Add those contributions: 0 + 32 = 32.
  7. As an unsigned pattern, the same eight bits represent 32.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011111; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11100000.
  11. Answer: signed(00100000) = 32.

Final answer: 32

Foundations · Problem 0034

Interpret 00100001 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100001 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 33.
  6. Add those contributions: 0 + 33 = 33.
  7. As an unsigned pattern, the same eight bits represent 33.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011110; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011111.
  11. Answer: signed(00100001) = 33.

Final answer: 33

Foundations · Problem 0035

Interpret 00100010 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100010 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 34.
  6. Add those contributions: 0 + 34 = 34.
  7. As an unsigned pattern, the same eight bits represent 34.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011101; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011110.
  11. Answer: signed(00100010) = 34.

Final answer: 34

Foundations · Problem 0036

Interpret 00100011 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100011 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 35.
  6. Add those contributions: 0 + 35 = 35.
  7. As an unsigned pattern, the same eight bits represent 35.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011100; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011101.
  11. Answer: signed(00100011) = 35.

Final answer: 35

Foundations · Problem 0037

Interpret 00100100 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100100 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 36.
  6. Add those contributions: 0 + 36 = 36.
  7. As an unsigned pattern, the same eight bits represent 36.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011011; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011100.
  11. Answer: signed(00100100) = 36.

Final answer: 36

Foundations · Problem 0038

Interpret 00100101 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100101 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 37.
  6. Add those contributions: 0 + 37 = 37.
  7. As an unsigned pattern, the same eight bits represent 37.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011010; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011011.
  11. Answer: signed(00100101) = 37.

Final answer: 37

Foundations · Problem 0039

Interpret 00100110 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100110 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 38.
  6. Add those contributions: 0 + 38 = 38.
  7. As an unsigned pattern, the same eight bits represent 38.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011001; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011010.
  11. Answer: signed(00100110) = 38.

Final answer: 38

Foundations · Problem 0040

Interpret 00100111 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00100111 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 39.
  6. Add those contributions: 0 + 39 = 39.
  7. As an unsigned pattern, the same eight bits represent 39.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11011000; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011001.
  11. Answer: signed(00100111) = 39.

Final answer: 39

Foundations · Problem 0041

Interpret 00101000 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101000 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 40.
  6. Add those contributions: 0 + 40 = 40.
  7. As an unsigned pattern, the same eight bits represent 40.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010111; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11011000.
  11. Answer: signed(00101000) = 40.

Final answer: 40

Foundations · Problem 0042

Interpret 00101001 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101001 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 41.
  6. Add those contributions: 0 + 41 = 41.
  7. As an unsigned pattern, the same eight bits represent 41.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010110; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010111.
  11. Answer: signed(00101001) = 41.

Final answer: 41

Foundations · Problem 0043

Interpret 00101010 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101010 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 42.
  6. Add those contributions: 0 + 42 = 42.
  7. As an unsigned pattern, the same eight bits represent 42.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010101; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010110.
  11. Answer: signed(00101010) = 42.

Final answer: 42

Foundations · Problem 0044

Interpret 00101011 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101011 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 43.
  6. Add those contributions: 0 + 43 = 43.
  7. As an unsigned pattern, the same eight bits represent 43.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010100; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010101.
  11. Answer: signed(00101011) = 43.

Final answer: 43

Foundations · Problem 0045

Interpret 00101100 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101100 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 44.
  6. Add those contributions: 0 + 44 = 44.
  7. As an unsigned pattern, the same eight bits represent 44.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010011; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010100.
  11. Answer: signed(00101100) = 44.

Final answer: 44

Foundations · Problem 0046

Interpret 00101101 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101101 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 45.
  6. Add those contributions: 0 + 45 = 45.
  7. As an unsigned pattern, the same eight bits represent 45.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010010; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010011.
  11. Answer: signed(00101101) = 45.

Final answer: 45

Foundations · Problem 0047

Interpret 00101110 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101110 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 46.
  6. Add those contributions: 0 + 46 = 46.
  7. As an unsigned pattern, the same eight bits represent 46.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010001; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010010.
  11. Answer: signed(00101110) = 46.

Final answer: 46

Foundations · Problem 0048

Interpret 00101111 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00101111 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 47.
  6. Add those contributions: 0 + 47 = 47.
  7. As an unsigned pattern, the same eight bits represent 47.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11010000; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010001.
  11. Answer: signed(00101111) = 47.

Final answer: 47

Foundations · Problem 0049

Interpret 00110000 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110000 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 48.
  6. Add those contributions: 0 + 48 = 48.
  7. As an unsigned pattern, the same eight bits represent 48.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001111; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11010000.
  11. Answer: signed(00110000) = 48.

Final answer: 48

Foundations · Problem 0050

Interpret 00110001 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110001 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 49.
  6. Add those contributions: 0 + 49 = 49.
  7. As an unsigned pattern, the same eight bits represent 49.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001110; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001111.
  11. Answer: signed(00110001) = 49.

Final answer: 49

Foundations · Problem 0051

Interpret 00110010 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110010 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 50.
  6. Add those contributions: 0 + 50 = 50.
  7. As an unsigned pattern, the same eight bits represent 50.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001101; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001110.
  11. Answer: signed(00110010) = 50.

Final answer: 50

Foundations · Problem 0052

Interpret 00110011 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110011 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 51.
  6. Add those contributions: 0 + 51 = 51.
  7. As an unsigned pattern, the same eight bits represent 51.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001100; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001101.
  11. Answer: signed(00110011) = 51.

Final answer: 51

Foundations · Problem 0053

Interpret 00110100 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110100 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 52.
  6. Add those contributions: 0 + 52 = 52.
  7. As an unsigned pattern, the same eight bits represent 52.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001011; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001100.
  11. Answer: signed(00110100) = 52.

Final answer: 52

Foundations · Problem 0054

Interpret 00110101 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110101 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 53.
  6. Add those contributions: 0 + 53 = 53.
  7. As an unsigned pattern, the same eight bits represent 53.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001010; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001011.
  11. Answer: signed(00110101) = 53.

Final answer: 53

Foundations · Problem 0055

Interpret 00110110 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110110 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 54.
  6. Add those contributions: 0 + 54 = 54.
  7. As an unsigned pattern, the same eight bits represent 54.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001001; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001010.
  11. Answer: signed(00110110) = 54.

Final answer: 54

Foundations · Problem 0056

Interpret 00110111 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00110111 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 55.
  6. Add those contributions: 0 + 55 = 55.
  7. As an unsigned pattern, the same eight bits represent 55.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11001000; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001001.
  11. Answer: signed(00110111) = 55.

Final answer: 55

Foundations · Problem 0057

Interpret 00111000 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111000 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 56.
  6. Add those contributions: 0 + 56 = 56.
  7. As an unsigned pattern, the same eight bits represent 56.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000111; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11001000.
  11. Answer: signed(00111000) = 56.

Final answer: 56

Foundations · Problem 0058

Interpret 00111001 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111001 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 57.
  6. Add those contributions: 0 + 57 = 57.
  7. As an unsigned pattern, the same eight bits represent 57.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000110; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000111.
  11. Answer: signed(00111001) = 57.

Final answer: 57

Foundations · Problem 0059

Interpret 00111010 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111010 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 58.
  6. Add those contributions: 0 + 58 = 58.
  7. As an unsigned pattern, the same eight bits represent 58.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000101; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000110.
  11. Answer: signed(00111010) = 58.

Final answer: 58

Foundations · Problem 0060

Interpret 00111011 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111011 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 59.
  6. Add those contributions: 0 + 59 = 59.
  7. As an unsigned pattern, the same eight bits represent 59.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000100; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000101.
  11. Answer: signed(00111011) = 59.

Final answer: 59

Foundations · Problem 0061

Interpret 00111100 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111100 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 60.
  6. Add those contributions: 0 + 60 = 60.
  7. As an unsigned pattern, the same eight bits represent 60.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000011; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000100.
  11. Answer: signed(00111100) = 60.

Final answer: 60

Foundations · Problem 0062

Interpret 00111101 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111101 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 61.
  6. Add those contributions: 0 + 61 = 61.
  7. As an unsigned pattern, the same eight bits represent 61.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000010; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000011.
  11. Answer: signed(00111101) = 61.

Final answer: 61

Foundations · Problem 0063

Interpret 00111110 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111110 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 62.
  6. Add those contributions: 0 + 62 = 62.
  7. As an unsigned pattern, the same eight bits represent 62.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000001; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000010.
  11. Answer: signed(00111110) = 62.

Final answer: 62

Foundations · Problem 0064

Interpret 00111111 as an 8-bit two’s complement value.

Try it on paper first. The worked answer is hidden below.

Reveal detailed solution →
  1. Treat 00111111 as exactly eight bits.
  2. For signed 8-bit values the leftmost column has weight −128, not +128.
  3. The remaining seven columns have weights 64, 32, 16, 8, 4, 2 and 1.
  4. The leading sign bit is 0, so its signed contribution is 0.
  5. The lower seven bits contribute 63.
  6. Add those contributions: 0 + 63 = 63.
  7. As an unsigned pattern, the same eight bits represent 63.
  8. The signed range for eight bits is −128 through +127.
  9. Bitwise inversion alone yields 11000000; inversion plus one wraps modulo 256.
  10. The eight-bit negated pattern is 11000001.
  11. Answer: signed(00111111) = 63.

Final answer: 63