2. Multiply each bit by its corresponding power of 2 and add all the terms up.
1000 1000 1000 1000 1000 1000 0100 1001(2) =
(1 × 231 + 0 × 230 + 0 × 229 + 0 × 228 + 1 × 227 + 0 × 226 + 0 × 225 + 0 × 224 + 1 × 223 + 0 × 222 + 0 × 221 + 0 × 220 + 1 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 1 × 215 + 0 × 214 + 0 × 213 + 0 × 212 + 1 × 211 + 0 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 1 × 20)(10) =
(2 147 483 648 + 0 + 0 + 0 + 134 217 728 + 0 + 0 + 0 + 8 388 608 + 0 + 0 + 0 + 524 288 + 0 + 0 + 0 + 32 768 + 0 + 0 + 0 + 2 048 + 0 + 0 + 0 + 0 + 64 + 0 + 0 + 8 + 0 + 0 + 1)(10) =
(2 147 483 648 + 134 217 728 + 8 388 608 + 524 288 + 32 768 + 2 048 + 64 + 8 + 1)(10) =
2 290 649 161(10)
The number 1000 1000 1000 1000 1000 1000 0100 1001(2) converted from an unsigned binary (in base 2) and written as a positive integer (with no sign) in decimal system (in base ten):
1000 1000 1000 1000 1000 1000 0100 1001(2) = 2 290 649 161(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.