## What is a ruler?

A ruler is one of the most common measuring instruments. It comes in many sizes and shapes, depending on what it is needed for. The yardstick is a long ruler (3 feet long), and a measuring tape is yet another type of ruler, made of flexible cloth or metal tape. Each may look different, but are used essentially the same way. Rulers and other measuring tapes might come in both standard and metric units. It is important to know the difference between these types of measurement.

### A ruler is a measuring stick marked with units for measuring along its longest edge.

These can be made of plastic, cardboard, metal, or fabric. marked units for measuring length along its edge using English (inches) or metric (centimeters) units of measurement.

- In the U.S. and the UK, a student’s rule is 12 inches, or one foot long.
- Learn how standard units work. Standard units are based on feet and inches.
- The inch is the basic unit in standard measurement.
- There are 12 inches in a foot. Most US rulers are 12 inches long.
- Most countries don’t use this unit of measurement any longer, preferring the metric system.

### Find the fraction of an inch markers. These delineate different fractions of an inch to help you measure as accurately as possible.

The smallest lines in between inch markers on a ruler represent 1/16 of an inch. The next largest lines represent 1/8 of an inch. The next largest lines show 1/4 inches. The longest line between inch markers shows 1/2 an inch.

- You will want to measure as closely an accurately to a fraction of an inch to get a true measurement of an object.

### Measuring an Object Using a Ruler

- Place the zero end of your rule at the end of your object. This will usually be on the left side.
- Make sure the end of the ruler is flush with your object.
- Use your left hand to hold it in place.
- Use your right hand to adjust the other end of the ruler.

### Move to the opposite side of the object you are measuring. You will now read the ruler to see how long the object is.

- Read the last number on your ruler that is alongside the object. This will indicate the “whole unit” length of the object, example: 8 inches.
- Count the number of fraction marks (dashes) the object you are measuring goes beyond the last whole number.
- If your ruler is marked in 1/8 inch increments, and you are 5 marks past the last whole unit number, you will be 5/8 inches beyond the 8, and your length will be read “8 and 5/8 inches’.
- Simplify fractions if you are able. For example, 4/16 of an inch is the same as 1/4 inch.

### Use a tape measure to measure between objects, for instance, walls. A retractable steel measuring tape would work best for this.

- Slide the zero end of the tape against one wall, or have a helper hold it, then pull out enough tape to reach the opposite wall.
- Here, you should have two sizes of numbers, the larger for feet (or meters), the smaller, for inches (or centimeters).
- Read the feet (or meters) first, inches (or cm), then fractions thereof.
- Example, a distance may read “12 feet, 5 and 1/2 inches”.