To change a Common Fraction to a Decimal. - Rule. Set the number representing the denominator of the given fraction on the line B, under the number representing the numerator: then above 1 on the line B the number of tenths or hundredths will be found on the line A.*

Example. - Change f to a decimal. We set the denominator 4 on the line B, under the numerator 3 on the line A (actually under 30): then above 1 on the line B we find 7 1/2 tenths, or 75 hundredths (.75), on the line A.

To change a, Decimal to a Common Fraction. - Rule. Set 1 on the line B, under the number of tenths or hundredths on the line A; then find the number on the line A which exactly coincides with any number on the line B; the number on the line A will be the numerator, and the number on the line B will be the denominator, of the required fraction.

* The right-hand half of the line A is generally used in stating the example; what really is 10 being considered as 1, and 20 being considered as 2, etc., unless the numerator of the given fraction should be larger than 10, in which case the numerator would be the number actually taken on the line A. In many cases, where the numerator and denominator contain more than one figure, considerable judgment must be used to determine whether the result obtained is tenths, hundredths, or thousandths. From 1 to 10 on the line A is divided into 10 parts, which are numbered from 1 to 10. In changing fractions to decimals, these parts usually represent tenths. These parts are subdivided into 10 parts each, which represent hundredths; there being 100 divisions, all told, from 1 to 10.

A FINE MODERN RESIDENCE. (For floor plans see back part of this book).

Example. - Change the decimal .625 to a common fraction. We set 1 on the line B, to 6 1/4 (6 1/4 tenths = .625) on the line A; then we find, toward the right-hand end of the rule, that 5 on the line A coincides with 8 on the line B: so we have 5/8 for the answer.