What are the steps to convert the base 2 signed binary number
1101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100(2) to a base 10 decimal system equivalent integer?
1. Is this a positive or a negative number?
1101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100 is the binary representation of a negative 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:
1101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100 = 101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
262
1 261
0 260
1 259
0 258
0 257
0 256
0 255
1 254
1 253
1 252
1 251
1 250
1 249
0 248
0 247
0 246
0 245
1 244
0 243
1 242
1 241
0 240
0 239
1 238
1 237
1 236
1 235
0 234
0 233
1 232
0 231
1 230
1 229
0 228
1 227
0 226
1 225
0 224
0 223
0 222
1 221
1 220
0 219
1 218
1 217
0 216
0 215
0 214
0 213
0 212
1 211
1 210
1 29
1 28
1 27
1 26
1 25
0 24
1 23
1 22
1 21
0 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100(2) =
(1 × 262 + 0 × 261 + 1 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 0 × 256 + 1 × 255 + 1 × 254 + 1 × 253 + 1 × 252 + 1 × 251 + 1 × 250 + 0 × 249 + 0 × 248 + 0 × 247 + 0 × 246 + 1 × 245 + 0 × 244 + 1 × 243 + 1 × 242 + 0 × 241 + 0 × 240 + 1 × 239 + 1 × 238 + 1 × 237 + 1 × 236 + 0 × 235 + 0 × 234 + 1 × 233 + 0 × 232 + 1 × 231 + 1 × 230 + 0 × 229 + 1 × 228 + 0 × 227 + 1 × 226 + 0 × 225 + 0 × 224 + 0 × 223 + 1 × 222 + 1 × 221 + 0 × 220 + 1 × 219 + 1 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 0 × 214 + 0 × 213 + 1 × 212 + 1 × 211 + 1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 0 × 21 + 0 × 20)(10) =
(4 611 686 018 427 387 904 + 0 + 1 152 921 504 606 846 976 + 0 + 0 + 0 + 0 + 36 028 797 018 963 968 + 18 014 398 509 481 984 + 9 007 199 254 740 992 + 4 503 599 627 370 496 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 0 + 0 + 0 + 0 + 35 184 372 088 832 + 0 + 8 796 093 022 208 + 4 398 046 511 104 + 0 + 0 + 549 755 813 888 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 0 + 0 + 8 589 934 592 + 0 + 2 147 483 648 + 1 073 741 824 + 0 + 268 435 456 + 0 + 67 108 864 + 0 + 0 + 0 + 4 194 304 + 2 097 152 + 0 + 524 288 + 262 144 + 0 + 0 + 0 + 0 + 0 + 4 096 + 2 048 + 1 024 + 512 + 256 + 128 + 64 + 0 + 16 + 8 + 4 + 0 + 0)(10) =
(4 611 686 018 427 387 904 + 1 152 921 504 606 846 976 + 36 028 797 018 963 968 + 18 014 398 509 481 984 + 9 007 199 254 740 992 + 4 503 599 627 370 496 + 2 251 799 813 685 248 + 1 125 899 906 842 624 + 35 184 372 088 832 + 8 796 093 022 208 + 4 398 046 511 104 + 549 755 813 888 + 274 877 906 944 + 137 438 953 472 + 68 719 476 736 + 8 589 934 592 + 2 147 483 648 + 1 073 741 824 + 268 435 456 + 67 108 864 + 4 194 304 + 2 097 152 + 524 288 + 262 144 + 4 096 + 2 048 + 1 024 + 512 + 256 + 128 + 64 + 16 + 8 + 4)(10) =
5 835 588 638 622 883 804(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100(2) = -5 835 588 638 622 883 804(10)
1101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100(2), Base 2 signed binary number, converted and written as a base 10 decimal system equivalent integer:
1101 0000 1111 1100 0010 1100 1111 0010 1101 0100 0110 1100 0001 1111 1101 1100(2) = -5 835 588 638 622 883 804(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.