A ruler is an instrument of measurement, which is of great use to students, housekeepers, housewives and professionals in fields like engineering and architecture. In a layman's language, a ruler is used to measure the distance between two points. If you look at any standard ruler, you can read measurements on it in either metric system or in the English system. A metric system is the one which measures in millimeters, centimeters and meters, while an English system measures in inches, yards and miles. Whether it is metric system or English system, it is very much possible to read measurements in fractions. The following Buzzle article offers tips for reading fractions on a ruler.

Finding Fractions on a Ruler

Let us start with the English system first. Look at the side marked "inches". On this side, each long vertical line marks an inch. In the middle of these long vertical lines, is a slightly small vertical line. This line marks half an inch. So, the line in between three and four inches is read as three and a half inches (3 and 1/2), the one between four and five is read as four and a half inches (4 and 1/2), the one between six and seven is read as six and a half inches (6 and 1/2) and so on.

Next, look at the smallest vertical lines on the inch side. Every inch is divided into eight such lines. Each of these lines represents one eighth of an inch (1/8). The distance between the longest vertical line and two such small lines is thus, two eighth (2/8) of an inch, which is in fact one-fourth of an inch 1/4), if you simplify the fraction. Similarly, four-eighth of an inch is actually half an inch (1/2) if you simplify the fraction.

Moving on to the other side of the ruler. Here, the metric system is used i.e. the units of measurement are centimeters and millimeters. One centimeter has ten millimeters, so each centimeter is divided into ten parts, marked by ten small vertical lines. The numbers along with the longest vertical lines on this side represent centimeters. The line in the middle represents five millimeters or half a centimeter. So, if the measurement reads three small vertical lines after the marked number five, it would be read as five and three-eighth centimeter i.e. 5 and 3/8 centimeters, in fractions. Similarly, six small lines after the marked number eight will be read as 8 and 6/10 centimeters. As centimeters are very rarely expressed in fractions while taking measurements, so concentrate more on learning how to read fractions in the English system.

Besides this, there are some other measurements that you should be aware of, such as, one inch is equal to two and a half centimeters (approximately), one meter is equal to hundred centimeters and one centimeter is equal to ten millimeters. Approximately, twelve inches (which is the normal size of a ruler) is equal to one foot and one foot is equal to 30.48 centimeters. One millimeter is equal to 0.0394 inches. Learn these measurements by heart, if you want to read a ruler and convert measurements from one unit to another.

There are some rulers on which, instead of eight lines, there are sixteen lines on the inch side. Such rulers measure fractions as one-sixteenth of an inch (1/16) or eight sixteenth (8/16 i.e. 1/2). Such rulers are now rarely used. So, you need not worry about them, instead mark different points on a paper and practice measuring fractions on them, with the help of the above suggested tips for reading a ruler.
Aastha Dogra
June 13, 2011