The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Education » math-teach

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: A problem with more than one method of solution
Replies: 2   Last Post: Oct 29, 1995 10:31 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Rex Boggs

Posts: 80
Registered: 12/6/04
A problem with more than one method of solution
Posted: Oct 28, 1995 6:30 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

"Find the area of skin on your hand. Discuss how accurate you think your
answer is."

I gave this question to year 10 students some years ago. The number of
different methods the students found was remarkable.

Most modelled the hand as a right prism, and traced around their hand to get
the 'base'. Some then overlaid a centimetre grid and counted squares, while
others divided it into rectangle and triangles and added the separate areas.
Most subtract out the area of the nails.

Getting the area of the 'perpendicular sides' caused a lot of discussion.
Some did it section by section (eg finger by finger), and even modelled the
tips of the fingers as semi-circles to get greater accuracy. Others
carefully laid a piece of string around their hand, and hence found the area
as a single piece.

There were some quite different solutions, however. One girl found a rubber
glove that fitted snugly. She cut it up and laid it flat and found the area
of that. Another painted her hand (!) and noted how much paint she used.
She then painted a rectangle that used the same amount of paint and
determined its area.

The discussions that ensued as to the most accurate method were very
passionate. The kids felt ownership of their solutions. and defended them



Rex Boggs | High above the hushed crowd, | Rex tried to remain focused.
| Still, he couldn't shake one
Glenmore High School | nagging thought: He was an
Rockhampton, Queensland | old dog and this was a new
Australia | trick - Gary Larson

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.