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:
0000 1010 0100 1001 = 000 1010 0100 1001
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
214
0 213
0 212
0 211
1 210
0 29
1 28
0 27
0 26
1 25
0 24
0 23
1 22
0 21
0 20
1
The number 0000 1010 0100 1001(2) converted from a signed binary (base two) and written as an integer in decimal system (base ten):
0000 1010 0100 1001(2) = 2 633(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.