Computers record and think every thing in binary.
We homo sapiens, generally have 10 fingers/toes, and we use 10 digits to count with 0 1 2 3 4 5 6 7 8 9
Then we use powers of ten for the bigger numbers 10 100 1000 10000 100000, in combination with the ten digits.
789215 is 7 x 106 + 8 x 105 + 9 x 104 + 2 x 103 + 1 x 102 + 5 x 100
Seven hundred and eighty nine thousand, two hundred and fifteen
We use a different set of symbols, letters, for general writing. In the Arabic alphabet there are 26 of these: a b c d e f g h I j k l m n o p q r s t u v w x y z in lower case
And another 26: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z in upper case.
We then have other symbols such as ! @ # $ % ^ & * ( ) used to convey other meanings.
We can also draw pictures and use colours to get our message across
Computers know two states: power signal on and off, and use two bits (binary digits) to count with 0 and 1
Powers of two are used for the bigger numbers
0 1 10 11 100 101 110 111 1000 1001
1010101010 is
(1 x 29) + (0 x 28) + (1 x 27) + (0 x 26) + (1 x 25) + (0 x 24) + (1 x 23) + (0 x 22) + (1 x 21) + (0 x 20)
In decimal this is
(1 * 512) + (0 * 256) + (1 * 128) + (0 * 64) + (1*32) + (0 * 16) + (1 * 8) + (0 * 4) + (1 * 2) + (0 * 1)
682