Use This Simple Idea to Help Students Understand Fractions of an Inch

Because rulers have so many small lines, they are difficult for students to understand and differentiate.  Because of this struggle,  I took a flat ruler and placed it on the copy machine and blew it up until an inch section was about as large as the page like below.

 

Then I cut off the centimeter section and the marks after the one inch mark.

 

Because linear measurement is more difficult for students to conceptualize, I relate it to parts of a whole by using this enlarged ruler.  Now that I have trimmed all of the sections off, students can see it as 1 WHOLE rectangular section as opposed to the daunting linear ruler.  I have students fold the ruler section into half along the half inch line.  When we study parts of a whole, we fold colored paper in half.  This make the ruler like parts of a whole instead of a linear model, so the ruler marks are easier for students to understand.

 

Next, students label the half point on the ruler where the paper folded.

 

Then students fold the halves into half to make fourths and label the fourths.  After labeling fourths, students begin to see equivalent fractions.

 

You could fold the fourths an additional time to make eighths also, but elementary students aren’t required to know eighths yet.

 

An additional fold would make sixteenths, but this is not really needed since all of the marks denote sixteenths.  Now you and your students can pull this ruler out anytime you need to refer to the fractional measurements.  The only thing to beware of is that students recognize this  fractional pattern repeats for every inch.  You will have to repeat the pattern for each number for students to recognize this.  Another error that can occur is that students leave the whole number off of their measurement and only think that the fractional marks stand for fractions alone.  Measuring to fractional inches greater than 1 and writing fractions greater than 1 need  to be modeled.  I hope this tidbit helps you and your students!

Edited 1/25/14:  I just found this great free ruler picture that would be great to use for the above activity.  You can see it  here.