2. Multiply each bit by its corresponding power of 2 and add all the terms up.
1010 0101 1000 0011 0011 1101 1111(2) =
(1 × 227 + 0 × 226 + 1 × 225 + 0 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 1 × 220 + 1 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 0 × 214 + 1 × 213 + 1 × 212 + 0 × 211 + 0 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20)(10) =
(134 217 728 + 0 + 33 554 432 + 0 + 0 + 4 194 304 + 0 + 1 048 576 + 524 288 + 0 + 0 + 0 + 0 + 0 + 8 192 + 4 096 + 0 + 0 + 512 + 256 + 128 + 64 + 0 + 16 + 8 + 4 + 2 + 1)(10) =
(134 217 728 + 33 554 432 + 4 194 304 + 1 048 576 + 524 288 + 8 192 + 4 096 + 512 + 256 + 128 + 64 + 16 + 8 + 4 + 2 + 1)(10) =
173 552 607(10)
The number 1010 0101 1000 0011 0011 1101 1111(2) converted from an unsigned binary (in base 2) and written as a positive integer (with no sign) in decimal system (in base ten):
1010 0101 1000 0011 0011 1101 1111(2) = 173 552 607(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.