Learning Resources LER 9301 Merkblatt

The Demonstration Ruler is great for modeling linear measurement.

Track measurements from 0–18 inches (in.) or 0–45 centimeters/centimetres (cm)
with the adjustable red band. Display the Demonstration Ruler on any magnetic
receptive surface, such as a white board.  

Suggested Use

Discuss with students some earlier methods of measurement, such as gauging
length with thumbs and feet. Guide students in measuring a few smaller objects
using the width of their thumbs. Record and compare the results. Lead students to
the conclusion that everyone’s thumb width is not the same. Therefore, a
“standard” unit, such as inches or centimeters/centimetres, is necessary for
everyone to achieve the same measurements. 

•  Familiarize students to the ruler and its markings.  

•  Be sure to identify by which units you are measuring (in. or cm).

•  If using a white board, draw a line on the board and position the ruler

underneath.  

•  Align the left end of the line to 0 on the left end of the ruler. 

•  When measuring, always hide the red band from view (as close to 0 as

possible).  

•  Gently slide the band from left to right and align the end of the red band with 

the end of the line or object being measured.  

•  Emphasize that the left end of the object or line being measured must always be

“flush” (even) with 0 on the left end of the ruler.  

•  Students should recognize that accurate

measurements begin on 0, which is usually 
(but not always) on the left edge of the ruler.

•  You may need to remove the ruler from the

magnetic surface while adjusting the length of
the red band.