1. Is this a positive or a negative number?
0000 0000 0000 0000 0000 0001 0101 1011 1001 0101 0100 0110 1010 0100 1111 0100 is the binary representation of a positive integer, on 64 bits (8 Bytes).
In a signed binary in one's complement representation, the first bit (the leftmost) indicates the sign, 1 = negative, 0 = positive.
2. 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 *
3. 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
0 246
0 245
0 244
0 243
0 242
0 241
0 240
1 239
0 238
1 237
0 236
1 235
1 234
0 233
1 232
1 231
1 230
0 229
0 228
1 227
0 226
1 225
0 224
1 223
0 222
1 221
0 220
0 219
0 218
1 217
1 216
0 215
1 214
0 213
1 212
0 211
0 210
1 29
0 28
0 27
1 26
1 25
1 24
1 23
0 22
1 21
0 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0000 0000 0000 0000 0000 0001 0101 1011 1001 0101 0100 0110 1010 0100 1111 0100(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 + 0 × 247 + 0 × 246 + 0 × 245 + 0 × 244 + 0 × 243 + 0 × 242 + 0 × 241 + 1 × 240 + 0 × 239 + 1 × 238 + 0 × 237 + 1 × 236 + 1 × 235 + 0 × 234 + 1 × 233 + 1 × 232 + 1 × 231 + 0 × 230 + 0 × 229 + 1 × 228 + 0 × 227 + 1 × 226 + 0 × 225 + 1 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 1 × 218 + 1 × 217 + 0 × 216 + 1 × 215 + 0 × 214 + 1 × 213 + 0 × 212 + 0 × 211 + 1 × 210 + 0 × 29 + 0 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 0 × 20)(10) =
(0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 1 099 511 627 776 + 0 + 274 877 906 944 + 0 + 68 719 476 736 + 34 359 738 368 + 0 + 8 589 934 592 + 4 294 967 296 + 2 147 483 648 + 0 + 0 + 268 435 456 + 0 + 67 108 864 + 0 + 16 777 216 + 0 + 4 194 304 + 0 + 0 + 0 + 262 144 + 131 072 + 0 + 32 768 + 0 + 8 192 + 0 + 0 + 1 024 + 0 + 0 + 128 + 64 + 32 + 16 + 0 + 4 + 0 + 0)(10) =
(1 099 511 627 776 + 274 877 906 944 + 68 719 476 736 + 34 359 738 368 + 8 589 934 592 + 4 294 967 296 + 2 147 483 648 + 268 435 456 + 67 108 864 + 16 777 216 + 4 194 304 + 262 144 + 131 072 + 32 768 + 8 192 + 1 024 + 128 + 64 + 32 + 16 + 4)(10) =
1 492 858 086 644(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0000 0000 0000 0000 0000 0001 0101 1011 1001 0101 0100 0110 1010 0100 1111 0100(2) = 1 492 858 086 644(10)
The signed binary number in one's complement representation 0000 0000 0000 0000 0000 0001 0101 1011 1001 0101 0100 0110 1010 0100 1111 0100(2) converted and written as an integer in decimal system (base ten):
0000 0000 0000 0000 0000 0001 0101 1011 1001 0101 0100 0110 1010 0100 1111 0100(2) = 1 492 858 086 644(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.