1. Is this a positive or a negative number?
0100 0000 0111 0000 0000 1100 1100 1100 1100 1100 1100 1100 1100 1100 1101 1101 is the binary representation of a positive integer, on 64 bits (8 Bytes).
In a signed binary in two's complement representation, the first bit (the leftmost) indicates the sign, 1 = negative, 0 = positive.
2. Get the binary representation in one's complement.
* Run this step only if the number is negative *
Note on binary subtraction rules:
11 - 1 = 10; 10 - 1 = 1; 1 - 0 = 1; 1 - 1 = 0.
Subtract 1 from the initial binary number.
* Not the case - the number is positive *
3. Get the binary representation of the positive (unsigned) number.
* Run this step only if the number is negative *
Flip all the bits of the signed binary in one's complement representation (reverse the digits) - replace the bits set on 1 with 0s and the bits on 0 with 1s:
* Not the case - the number is positive *
4. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
263
0 262
1 261
0 260
0 259
0 258
0 257
0 256
0 255
0 254
1 253
1 252
1 251
0 250
0 249
0 248
0 247
0 246
0 245
0 244
0 243
1 242
1 241
0 240
0 239
1 238
1 237
0 236
0 235
1 234
1 233
0 232
0 231
1 230
1 229
0 228
0 227
1 226
1 225
0 224
0 223
1 222
1 221
0 220
0 219
1 218
1 217
0 216
0 215
1 214
1 213
0 212
0 211
1 210
1 29
0 28
0 27
1 26
1 25
0 24
1 23
1 22
1 21
0 20
1
5. Multiply each bit by its corresponding power of 2 and add all the terms up.
0100 0000 0111 0000 0000 1100 1100 1100 1100 1100 1100 1100 1100 1100 1101 1101(2) =
(0 × 263 + 1 × 262 + 0 × 261 + 0 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 0 × 256 + 0 × 255 + 1 × 254 + 1 × 253 + 1 × 252 + 0 × 251 + 0 × 250 + 0 × 249 + 0 × 248 + 0 × 247 + 0 × 246 + 0 × 245 + 0 × 244 + 1 × 243 + 1 × 242 + 0 × 241 + 0 × 240 + 1 × 239 + 1 × 238 + 0 × 237 + 0 × 236 + 1 × 235 + 1 × 234 + 0 × 233 + 0 × 232 + 1 × 231 + 1 × 230 + 0 × 229 + 0 × 228 + 1 × 227 + 1 × 226 + 0 × 225 + 0 × 224 + 1 × 223 + 1 × 222 + 0 × 221 + 0 × 220 + 1 × 219 + 1 × 218 + 0 × 217 + 0 × 216 + 1 × 215 + 1 × 214 + 0 × 213 + 0 × 212 + 1 × 211 + 1 × 210 + 0 × 29 + 0 × 28 + 1 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 0 × 21 + 1 × 20)(10) =
(0 + 4 611 686 018 427 387 904 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 18 014 398 509 481 984 + 9 007 199 254 740 992 + 4 503 599 627 370 496 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 8 796 093 022 208 + 4 398 046 511 104 + 0 + 0 + 549 755 813 888 + 274 877 906 944 + 0 + 0 + 34 359 738 368 + 17 179 869 184 + 0 + 0 + 2 147 483 648 + 1 073 741 824 + 0 + 0 + 134 217 728 + 67 108 864 + 0 + 0 + 8 388 608 + 4 194 304 + 0 + 0 + 524 288 + 262 144 + 0 + 0 + 32 768 + 16 384 + 0 + 0 + 2 048 + 1 024 + 0 + 0 + 128 + 64 + 0 + 16 + 8 + 4 + 0 + 1)(10) =
(4 611 686 018 427 387 904 + 18 014 398 509 481 984 + 9 007 199 254 740 992 + 4 503 599 627 370 496 + 8 796 093 022 208 + 4 398 046 511 104 + 549 755 813 888 + 274 877 906 944 + 34 359 738 368 + 17 179 869 184 + 2 147 483 648 + 1 073 741 824 + 134 217 728 + 67 108 864 + 8 388 608 + 4 194 304 + 524 288 + 262 144 + 32 768 + 16 384 + 2 048 + 1 024 + 128 + 64 + 16 + 8 + 4 + 1)(10) =
4 643 225 289 567 816 925(10)
6. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0100 0000 0111 0000 0000 1100 1100 1100 1100 1100 1100 1100 1100 1100 1101 1101(2) = 4 643 225 289 567 816 925(10)
The signed binary number in two's complement representation 0100 0000 0111 0000 0000 1100 1100 1100 1100 1100 1100 1100 1100 1100 1101 1101(2) converted and written as an integer in decimal system (base ten):
0100 0000 0111 0000 0000 1100 1100 1100 1100 1100 1100 1100 1100 1100 1101 1101(2) = 4 643 225 289 567 816 925(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.