How does a binary number be presented?

Answer 1

Binary numbers start with a column with the value of 1 on the right side. The next column, to the left, has double the value (which is 2), the next left doubles again (which is 4), then 8, 16, 32, 64, 128 etc. The inclusion of a number 1 in a column means that the number should be included in the total. The inclusion of a zero in a column means that the number should not be counted. Using just this combination of 1s and 0s any number can be represented. For example...
1 = 1
2 = 10
3 = 11
4 = 100
10 = 1010
15 = 1111
65 = 1000001

To convert the numbers from binary to decimal you can simply use a calculator and starting at the right side of the binary number if the first digit is 1 then add 1 to your calculator. If it is zero don't add anything, move left to the next column, if there is a 1 in this column add 2 to your total on your calculator, if it is a zero don't add anything, continue doing this, doubling the value for each column and adding the number if there is a 1 and ignoring it if there is a zero. For example....
The binary number 1100, starting at the right has 0 in the 1 column, 0 in the 2 column, 1 in the 4 column and 1 in the 8 column, so you would ignore 1 and 2 and simply add 4 + 8, giving your a value of 12, which is correct.