計概 3題補數問題

Question

十進制300.425畫成二進制
求出二進制10010001.1101011的2補數
使用2補數計算-12-(-34)

Answer 1

300.425
= 256 + 32 + 8 + 4 + .25 + .125 + .03125 + .015625 + .001953125 + .0009765625 + 0.0001220703125 + 0.0000732421875
= 28 + 25 + 23 + 22 + 2-2 + 2-3 + 2-5 + 2-6 + 2-9 + 2-10 + 2-13 + 0.0000732421875
≈ 100101100.0110110011001
10010001.1101011 (1's)-> 01101110.0010100 (2's)-> 01101110.0010101
-12d- (-34)d = -001100b - (-100010b) [1's] -> 110011b + 100010b [2's] -> 110100b + 100010b = 010110b = 22d