What are the steps to convert the base 2 signed binary number
0111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111(2) to a base 10 decimal system equivalent integer?
1. Is this a positive or a negative number?
0111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111 is the binary representation of a positive integer, on 64 bits (8 Bytes).
- In a signed binary, the first bit (the leftmost) is reserved for the sign, 1 = negative, 0 = positive. This bit does not count when calculating the absolute value.
2. Construct the unsigned binary number.
Exclude the first bit (the leftmost), that is reserved for the sign:
0111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111 = 111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
262
1 261
1 260
1 259
0 258
0 257
0 256
1 255
1 254
0 253
0 252
1 251
1 250
1 249
1 248
1 247
0 246
0 245
0 244
0 243
1 242
0 241
0 240
1 239
0 238
0 237
0 236
0 235
0 234
1 233
1 232
1 231
0 230
1 229
0 228
0 227
0 226
1 225
0 224
1 223
1 222
1 221
1 220
1 219
0 218
1 217
1 216
1 215
1 214
0 213
0 212
1 211
1 210
1 29
1 28
0 27
1 26
1 25
1 24
1 23
0 22
1 21
1 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111(2) =
(1 × 262 + 1 × 261 + 1 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 1 × 256 + 1 × 255 + 0 × 254 + 0 × 253 + 1 × 252 + 1 × 251 + 1 × 250 + 1 × 249 + 1 × 248 + 0 × 247 + 0 × 246 + 0 × 245 + 0 × 244 + 1 × 243 + 0 × 242 + 0 × 241 + 1 × 240 + 0 × 239 + 0 × 238 + 0 × 237 + 0 × 236 + 0 × 235 + 1 × 234 + 1 × 233 + 1 × 232 + 0 × 231 + 1 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 1 × 226 + 0 × 225 + 1 × 224 + 1 × 223 + 1 × 222 + 1 × 221 + 1 × 220 + 0 × 219 + 1 × 218 + 1 × 217 + 1 × 216 + 1 × 215 + 0 × 214 + 0 × 213 + 1 × 212 + 1 × 211 + 1 × 210 + 1 × 29 + 0 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 1 × 21 + 1 × 20)(10) =
(4 611 686 018 427 387 904 + 2 305 843 009 213 693 952 + 1 152 921 504 606 846 976 + 0 + 0 + 0 + 72 057 594 037 927 936 + 36 028 797 018 963 968 + 0 + 0 + 4 503 599 627 370 496 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 562 949 953 421 312 + 281 474 976 710 656 + 0 + 0 + 0 + 0 + 8 796 093 022 208 + 0 + 0 + 1 099 511 627 776 + 0 + 0 + 0 + 0 + 0 + 17 179 869 184 + 8 589 934 592 + 4 294 967 296 + 0 + 1 073 741 824 + 0 + 0 + 0 + 67 108 864 + 0 + 16 777 216 + 8 388 608 + 4 194 304 + 2 097 152 + 1 048 576 + 0 + 262 144 + 131 072 + 65 536 + 32 768 + 0 + 0 + 4 096 + 2 048 + 1 024 + 512 + 0 + 128 + 64 + 32 + 16 + 0 + 4 + 2 + 1)(10) =
(4 611 686 018 427 387 904 + 2 305 843 009 213 693 952 + 1 152 921 504 606 846 976 + 72 057 594 037 927 936 + 36 028 797 018 963 968 + 4 503 599 627 370 496 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 562 949 953 421 312 + 281 474 976 710 656 + 8 796 093 022 208 + 1 099 511 627 776 + 17 179 869 184 + 8 589 934 592 + 4 294 967 296 + 1 073 741 824 + 67 108 864 + 16 777 216 + 8 388 608 + 4 194 304 + 2 097 152 + 1 048 576 + 262 144 + 131 072 + 65 536 + 32 768 + 4 096 + 2 048 + 1 024 + 512 + 128 + 64 + 32 + 16 + 4 + 2 + 1)(10) =
8 187 272 574 426 128 119(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111(2) = 8 187 272 574 426 128 119(10)
0111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111(2), Base 2 signed binary number, converted and written as a base 10 decimal system equivalent integer:
0111 0001 1001 1111 0000 1001 0000 0111 0100 0101 1111 0111 1001 1110 1111 0111(2) = 8 187 272 574 426 128 119(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.