4, 5, 6, 7, 8, AND 9 AND BY THE COMBINATIONS OF THEM. FOR EXAMPLE,...

3, 4, 5, 6, 7, 8, and 9 and by the combinations of them. For example, 247 – two hundred and forty seven - is

a number formed by three digits. Parts of numbers smaller than 1 are sometimes expressed in terms of

fraction, but in scientific usage they are given as decimals. This is because it is easier to perform the various

mathematical operations if decimals are used instead of fractions. The main operations are: to add, subtract,

multiply and divide; to square, cube, or raise to any other power; to take a square, cube, or any other root,

and to find a ratio or proportion between pairs of numbers or a series of numbers. Thus, the decimal, or ten-

scale, system is used for scientific purposes throughout the world, even in countries whose national systems

of weights and measurements are based upon other scales. The other scale in general use nowadays is the

binary, or two-scale, in which numbers are expressed by combinations of only two digits, a and 1. Thus, in

the binary scale, 2 is expressed as 010, 3 is given as 011, 4 is represented as 100, etc. This scale is perfectly

adapted to the "off-on" pulse of electricity, so it is widely used in electronic computers. Because of its

simplicity it is often called "the lazy schoolboy's dream "!