1. Is this a positive or a negative number?
0000 0000 0000 0000 1010 1001 1001 1011 1000 1101 1000 1100 1001 0001 1110 1011 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
0 261
0 260
0 259
0 258
0 257
0 256
0 255
0 254
0 253
0 252
0 251
0 250
0 249
0 248
0 247
1 246
0 245
1 244
0 243
1 242
0 241
0 240
1 239
1 238
0 237
0 236
1 235
1 234
0 233
1 232
1 231
1 230
0 229
0 228
0 227
1 226
1 225
0 224
1 223
1 222
0 221
0 220
0 219
1 218
1 217
0 216
0 215
1 214
0 213
0 212
1 211
0 210
0 29
0 28
1 27
1 26
1 25
1 24
0 23
1 22
0 21
1 20
1
5. Multiply each bit by its corresponding power of 2 and add all the terms up.
0000 0000 0000 0000 1010 1001 1001 1011 1000 1101 1000 1100 1001 0001 1110 1011(2) =
(0 × 263 + 0 × 262 + 0 × 261 + 0 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 0 × 256 + 0 × 255 + 0 × 254 + 0 × 253 + 0 × 252 + 0 × 251 + 0 × 250 + 0 × 249 + 0 × 248 + 1 × 247 + 0 × 246 + 1 × 245 + 0 × 244 + 1 × 243 + 0 × 242 + 0 × 241 + 1 × 240 + 1 × 239 + 0 × 238 + 0 × 237 + 1 × 236 + 1 × 235 + 0 × 234 + 1 × 233 + 1 × 232 + 1 × 231 + 0 × 230 + 0 × 229 + 0 × 228 + 1 × 227 + 1 × 226 + 0 × 225 + 1 × 224 + 1 × 223 + 0 × 222 + 0 × 221 + 0 × 220 + 1 × 219 + 1 × 218 + 0 × 217 + 0 × 216 + 1 × 215 + 0 × 214 + 0 × 213 + 1 × 212 + 0 × 211 + 0 × 210 + 0 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 1 × 21 + 1 × 20)(10) =
(0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 140 737 488 355 328 + 0 + 35 184 372 088 832 + 0 + 8 796 093 022 208 + 0 + 0 + 1 099 511 627 776 + 549 755 813 888 + 0 + 0 + 68 719 476 736 + 34 359 738 368 + 0 + 8 589 934 592 + 4 294 967 296 + 2 147 483 648 + 0 + 0 + 0 + 134 217 728 + 67 108 864 + 0 + 16 777 216 + 8 388 608 + 0 + 0 + 0 + 524 288 + 262 144 + 0 + 0 + 32 768 + 0 + 0 + 4 096 + 0 + 0 + 0 + 256 + 128 + 64 + 32 + 0 + 8 + 0 + 2 + 1)(10) =
(140 737 488 355 328 + 35 184 372 088 832 + 8 796 093 022 208 + 1 099 511 627 776 + 549 755 813 888 + 68 719 476 736 + 34 359 738 368 + 8 589 934 592 + 4 294 967 296 + 2 147 483 648 + 134 217 728 + 67 108 864 + 16 777 216 + 8 388 608 + 524 288 + 262 144 + 32 768 + 4 096 + 256 + 128 + 64 + 32 + 8 + 2 + 1)(10) =
186 485 559 824 875(10)
6. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0000 0000 0000 0000 1010 1001 1001 1011 1000 1101 1000 1100 1001 0001 1110 1011(2) = 186 485 559 824 875(10)
The signed binary number in two's complement representation 0000 0000 0000 0000 1010 1001 1001 1011 1000 1101 1000 1100 1001 0001 1110 1011(2) converted and written as an integer in decimal system (base ten):
0000 0000 0000 0000 1010 1001 1001 1011 1000 1101 1000 1100 1001 0001 1110 1011(2) = 186 485 559 824 875(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.