F.1 ~ F.2 math (2)

Convert 2E1(16) into a denary number.
2E1(16) = 10 1110 0001(2)


110110(2) = 11 0110(2) = 36(16)
37(10) = 32 + 5 = 2x16 + 5 = 25(16)
444(10) = 256 + 176 + 12 = 1x162 + 11x16 + 12 = 1BC(16)

Convert the following binary numbers into hexadecimal numbers.
(a) 1011011(2)
1011011(2) = 101 1011(2) = 5D(16)
(b) 111101110101(2)
111101110101(2) = 1111 0111 0101(2) = F75(16)

Convert the following hexadecimal numbers into binary numbers.
(a) 9C(16) = 1001 1100(2)
(b) 24D(16) = 10 0100 1101(2)

以上問題中2進數和16進數是用下列對換表轉換
0000 = 0
0001 = 1
0010 = 2
0011 = 3
0100 = 4
0101 = 5
0110 = 6
0111 = 7
1000 = 8
1001 = 9
1010 = A
1011 = B
1100 = C
1101 = D
1110 = E
1111 = F
所以將二進數化十六進數是，我是由最右的位置每四個二進數作一組，後用上表直接變成十六數數，而16進數化二進數亦是用上表，每個十六進的數字變回一組四位的二進數。以上計法是全用心算，無用計數機。