To begin the lesson, read How Big Is a Foot?
to students. This amusing story tells of a king who wants to have a bed
made just the right size for his queen. He measures her width and
length with his king-size feet. The job of building the bed falls to a little apprentice who
carefully uses the king's dimensions, but uses his little feet as the
unit. Students enjoy explaining why the bed turns out to be too small
for the queen and posing solutions to the dilemma.
Explain to the students that, although this is a fictional story, it
is based upon fact. Our standard unit of measure, the foot, actually
did come from making a model of a king's foot; and the standardized
tool became known as a "ruler." Show a ruler so students can imagine a
Have each student trace around his or her shoe on construction paper
and cut out about six of these paper feet. Tape them heel to toe. Let
the students use this new "six-foot" measure to find and record the
length of common objects around the room.
After about ten minutes, lead the class in a discussion, comparing
their measurements. Chart the data to use as a visual reference. Ask
questions that help students compare their findings, for example:
- Who measured the height of the desk? What did you find?
- Who found a different measurement for the height of the desk?
- Why do you think it was different from ____'s?
- Is the desk really taller for ____ than for ____?
Show the students a variety of rulers (wooden, plastic, metal). Ask,
does anyone have an idea about why we use rulers instead of paper feet
taped together? Enjoy the idea-sharing! Note levels of thinking,
reasoning, and creativity.
Then, explain that inches began in medieval England and were
based upon the width of the human thumb. Thumbs were excellent
measuring tools because even the poorest individuals had them available
when they went to market.
Ask students to draw, along the edge of their construction paper, a
line equal to the width of their thumbs. Cut the edge off the paper
(about an inch wide), and accordion-fold the strip to show 12 student