How do rulers work

This would mean the strand is If you want any extra assistance with learning how to read a ruler in cm or inches, videos and worksheets can be excellent resources. All of these resources, in addition to the handful of practice questions we gave you above, should be enough to get you reading a ruler in no time at all! Got questions about decimals and fractions?

Our expert guides will teach you how to convert decimals to fractions and how to add and subtract fractions. Metric rulers usually have only centimeters and millimeters on them. But did you know there's an even tinier unit called nanometers? Learn how to convert nanometers to meters and other measurements with our in-depth guide. Ever seen Roman numerals but didn't know how to read them? Check out our detailed guide and you'll be on your way to understanding this ancient numerical system!

She is passionate about education, writing, and travel. Our new student and parent forum, at ExpertHub. See how other students and parents are navigating high school, college, and the college admissions process. Ask questions; get answers. How to Get a Perfect , by a Perfect Scorer. Score on SAT Math. Score on SAT Reading. Score on SAT Writing. What ACT target score should you be aiming for?

How to Get a Perfect 4. How to Write an Amazing College Essay. A Comprehensive Guide. Choose Your Test. How to Read a Ruler in Inches and Centimeters.

How to Read a Ruler: Imperial vs Metric There are two types of rulers you can use: the inch, or imperial, ruler and the centimeter, or metric, ruler. These are not actual lengths of measurement but will give distances to scale from a size ratio. For example "1 inch equals 1 foot" ratio , "1 mm equals 1 cm" or "1 cm equals 1 meter" These are used for drawing precisely scaled blueprints and building plans.

Method 2. Learn how U. Customary units work. Customary units, sometimes called "Standard Units" in the U. S, are based on feet and inches. There are 12 inches in a foot. Most rulers are 12 inches long. Longer rulers, which are 3 feet long or 36 inches long, equal to one yard are called yardsticks. Most countries don't use this unit of measurement any longer, preferring the metric system. Find the inches unit on your ruler.

These are larger lines next to large numbers on your ruler. Most student rulers can measure up to 12 inches at a time. You will want to measure accurately, so you will have to know more than just where the inch markers are.

Find the fraction of an inch markers. These delineate different fractions of an inch to help you measure as accurately as possible. You will want to measure as closely an accurately to a fraction of an inch to get a true measurement of an object. Method 3. Understand what SI-units are. These are the units of measurement used in the metric system. This is close in size, but not exactly, a yard, with one yard being 0.

The main units of measurement in the metric system are millimeters and centimeters. There are centimeters in a meter, or millimeters. Find the centimeter lines on a ruler. These are the lines that have a long line with a number beside it. Centimeters are smaller than inches. There are 2. The distance between two centimeter lines is one centimeter. Most standard rulers are either 20, 25 or 30 centimeters long. Meter sticks have centimeters.

The abbreviation for centimeters is cm. Learn to read the smaller units. The smaller units on a metric ruler are called millimeters. There are 10 mm in a centimeter. Therefore, 5 mm is half of a centimeter. Remember that all measurements in metric are in units of This is an easy trick to remember for measuring in metric. There are 10 mm in a cm. The millimeter is the smallest unit of measurement on most metric rulers. Method 4. Measure with a ruler or tape measure.

Find an object or distance between two points you want to measure. This can be a length of wood, string, or cloth, or a line on a sheet of paper. Rulers and yardsticks are better to use on hard flat surfaces. If you are measuring a person for clothing it is best to use a flexible tool like a seamstress' tape. Long distances can be measured using a measuring tape.

Place the zero end of your rule at the end of your object. This will usually be on the left side. 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.

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. Simplify fractions if you are able. Use a metric or decimal rule with a metric ruler. You will be reading measurements in units of 10, following the metric system. Go to the nearest centimeter line. That will indicate the "whole unit" length. For example, 10 centimeters. In the case of a metric rule marked in centimeters cm , read the intermediate marks as millimeters mm.

Read how many intermediate marks go past your whole unit measurement to the edge of the object. For example, if you measured an object that was 10cm plus 8mm, your measurement would be Log in Social login does not work in incognito and private browsers. Please log in with your username or email to continue. No account yet?

Create an account. Edit this Article. We use cookies to make wikiHow great. By using our site, you agree to our cookie policy. Cookie Settings. Learn why people trust wikiHow. Download Article Explore this Article methods. Tips and Warnings. Related Articles. Article Summary. Method 1. Get an inch ruler. You'll know it's an inch ruler because it will have 12 lines that denote inches on the ruler.

Each foot is broken down into inches. Each inch is broken down into 15 smaller marks, equaling 16 marks in total for each inch on the ruler. Make sure you read the ruler from left to right. If you are measuring something, align it with the left side of the zero mark on the ruler.

The left side of the line where the object ends will be its measurement in inches. Learn the inch marks. A ruler is made up of 12 inch marks. These are typically the numbered marks on the ruler and are denoted by the longest lines on the ruler.

For example, if you need to measure a nail, place one end directly on the left side of the ruler. If it ends directly above the long line next to the large number 5, then the nail is 5 inches long. In total, there are 24 of these marks on a 12 inch ruler. Mark where the tip of the pencil lead ends on the ruler. There are a total of 48 of these marks on a 12 inch ruler. In total, there are 96 of these marks on a 12 inch ruler.

These are also the smallest lines on the ruler. There are a total of of these lines on the ruler. If you plan on measuring things that are small or you need to be extremely accurate, make sure the ruler you use has these marks. Method 2. Get a metric ruler. A metric ruler is based on the International System of Units SI , sometimes called the metric system, and is divded into either millimeters or centimeters instead of inches. Rulers are often 30 centimeters long, which are designated by large numbers on the ruler.

Between each centimeter cm mark, there should be 10 smaller marks called millimeters mm. If you are measuring an object, align it with the left side of the zero mark on the ruler.

The left side of the line where the object ends will be its measurement in centimeters. This way the line thickness will not affect the measurement. Unlike with the English ruler, the measurements for the metric ruler are written in decimals instead of fractions.

Learn the centimeter marks. The large numbers next to the longest lines on the ruler denote the centimeter marks. A metric ruler has 30 of these marks. For example, place the bottom of a crayon on the far left side of the ruler to measure it. Note where the tip falls.