How to Read a Ruler

So you want to know how to read a ruler? A ruler is a measuring device which will identify the exact length of an object, given that the object is in adequate proportion to the item requiring measurement. The following article will provide adequate instruction on how to read a ruler based on the American Standard ruler which measures exactly one foot, or twelve inches, in length.

Difficulty: Easy

Instructions

1. 
   How to Read a Ruler : End Close-up

   Position the length of the item to be measured parallel to the ruler as seen in the image. One extent of the item must be in line with the very first mark. If you are measuring a pen, one end should be lined up as per the photo and the other in line with the measure.

2. The longest lines identify the inches. Traditionally the inches are accompanied by a number which identifies the amount of inches long or wide that the item is. Do not count any lines past the length of the item. See the photo. The pen is over five inches, not six because it does not quite reach the six mark.

3. Each of the smaller lines identifies a fraction of an inch. They get shorter as the increment gets smaller. The shortest lines are a sixteenth of an inch. The different line increments are a sixteenth, an eighth, a quarter and a half. Figure out which line the item lines up with best and identify the increment. In this case it lines up with an eighth inch mark.

4. 
   How to Read a Ruler : Fraction Close-up

   Count the marks, within that inch only, which are of the same length or increment. In the photo, you can see that the pen covers seven of these increments.

5. Add the inches to the fraction of an inch. Now that we know how to read a ruler, we can derive that the pen is 5 and seven eights inches long.

Tips & Warnings

• How to Read a Ruler for items which are long: If your item is longer than the ruler, use a piece of tape to mark one foot segments. Count these as one foot each and add this to the remainder. Example: 3 foot, 4 and a quarter inches.
• How to Read a Ruler for items which are really short: If you have an item under an inch, you may want to use a magnifying glass in order to get an accurate reading.
• It is extremely important to know how to read a ruler. There is a saying measure twice, cut once. The idea is that mistakes can be made even if you know how to read a ruler.

[fantasyguy]

on 7/1/2009 Loved the article, such a simple device that challenges so many. Thanks :)

[brandy1123]

on 12/4/2008 great refresher course

[larryzafran]

on 12/2/2008 This is very useful. I'm a math tutor, and many of my students have no idea how to read a ruler. I think that it mostly has to do with confusion about fractions, but of course there is also the issue of reading the tickmarks on the ruler.

[SageKat]

on 11/30/2008 I was perplexed, discombobulated and finally transfixed by this article.

[RiteNow]

on 11/10/2008 Great idea!!! Thanks 5*