What are the steps to convert the base 2 signed binary number
1111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100(2) to a base 10 decimal system equivalent integer?
1. Is this a positive or a negative number?
1111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100 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:
1111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100 = 111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100
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
0 254
0 253
1 252
0 251
0 250
0 249
1 248
0 247
1 246
0 245
1 244
1 243
1 242
0 241
1 240
1 239
1 238
1 237
0 236
1 235
1 234
0 233
1 232
0 231
0 230
1 229
1 228
1 227
0 226
1 225
0 224
0 223
0 222
1 221
1 220
0 219
0 218
1 217
0 216
0 215
0 214
0 213
1 212
0 211
1 210
0 29
1 28
1 27
0 26
1 25
0 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.
111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100(2) =
(1 × 262 + 1 × 261 + 1 × 260 + 0 × 259 + 0 × 258 + 0 × 257 + 1 × 256 + 0 × 255 + 0 × 254 + 1 × 253 + 0 × 252 + 0 × 251 + 0 × 250 + 1 × 249 + 0 × 248 + 1 × 247 + 0 × 246 + 1 × 245 + 1 × 244 + 1 × 243 + 0 × 242 + 1 × 241 + 1 × 240 + 1 × 239 + 1 × 238 + 0 × 237 + 1 × 236 + 1 × 235 + 0 × 234 + 1 × 233 + 0 × 232 + 0 × 231 + 1 × 230 + 1 × 229 + 1 × 228 + 0 × 227 + 1 × 226 + 0 × 225 + 0 × 224 + 0 × 223 + 1 × 222 + 1 × 221 + 0 × 220 + 0 × 219 + 1 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 0 × 214 + 1 × 213 + 0 × 212 + 1 × 211 + 0 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 0 × 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 + 0 + 0 + 9 007 199 254 740 992 + 0 + 0 + 0 + 562 949 953 421 312 + 0 + 140 737 488 355 328 + 0 + 35 184 372 088 832 + 17 592 186 044 416 + 8 796 093 022 208 + 0 + 2 199 023 255 552 + 1 099 511 627 776 + 549 755 813 888 + 274 877 906 944 + 0 + 68 719 476 736 + 34 359 738 368 + 0 + 8 589 934 592 + 0 + 0 + 1 073 741 824 + 536 870 912 + 268 435 456 + 0 + 67 108 864 + 0 + 0 + 0 + 4 194 304 + 2 097 152 + 0 + 0 + 262 144 + 0 + 0 + 0 + 0 + 8 192 + 0 + 2 048 + 0 + 512 + 256 + 0 + 64 + 0 + 16 + 0 + 4 + 0 + 0)(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 + 9 007 199 254 740 992 + 562 949 953 421 312 + 140 737 488 355 328 + 35 184 372 088 832 + 17 592 186 044 416 + 8 796 093 022 208 + 2 199 023 255 552 + 1 099 511 627 776 + 549 755 813 888 + 274 877 906 944 + 68 719 476 736 + 34 359 738 368 + 8 589 934 592 + 1 073 741 824 + 536 870 912 + 268 435 456 + 67 108 864 + 4 194 304 + 2 097 152 + 262 144 + 8 192 + 2 048 + 512 + 256 + 64 + 16 + 4)(10) =
8 152 284 822 424 005 460(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100(2) = -8 152 284 822 424 005 460(10)
1111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100(2), Base 2 signed binary number, converted and written as a base 10 decimal system equivalent integer:
1111 0001 0010 0010 1011 1011 1101 1010 0111 0100 0110 0100 0010 1011 0101 0100(2) = -8 152 284 822 424 005 460(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.