Lesson12 - ENJOY MATHEMATICS in 3D

Outline: "cutting cylinder s and cones , and observation of the cut surfaces"

... Learning activities

... Teacher's instructions/guide

... Evaluation (expected student responses)

Regarding the necessary software data for using "Cabri 3D File" and "Flash Movie" on the pages, please review [Installing necessary software] .

Learning content

	Introduce three-dimensional shapes found in daily li fe using a means such as projected images.
	Show a trowel as an actual example of skillfully using a shape created by cutting a cone.
	A fter reconfirming that an ellipse is also created when a cylinder is cut diagonally, introduce by showing an actual object that the method is used in drap ery, a three-dimen s ional cutting method used f or clothes.
	Objects created by diagonally cutting a cylinder or cone have a tilted center of balance, so they do not easily roll over.
	By using an actual object, introduce that, to create a paper pattern whose cut surface will be an ellipse, the cut needs to be done in the form of a sine curve.
	Present a photo of the head office of Fuji Television Network, Inc., and allow time to take on the challenge of drawing it using Cabri 3D.
	Draw the shape of the head office of Fuji Television Network, Inc. using Cabri 3D.
	Request that students review previously learned material and to summarize them in the worksheet from the following points of view . (1) Through learning the construction and cutting of three-dimensional figures, what kind of image did he or she have regarding the s hape (three-dimensional figures)? (2)By observing and thinking about shapes seen in daily life , what point (ability) of oneself does he or she think has or has not been enhanced? (3) Frank impression s of the experience of using Cabri 3D. [Note] This class aims at allowing time to freely us e Cabri 3D so as to provide an enjoyable learning opportunity for the students. It is an option for when there is some spare time.

Expected responses from the students

A	Columns such as canned juice are often seen.
B	A ball is sphere-shaped.
C	C one s used in physical education are con ical .
D	I did not know that a trowel is the shape created by cutting a cone.
E	The container s to stand payment slip s in seen in such places as restaurant s are created by diagonally cutting a cylinder.
F	Objects created by diagonally cutting a cylinder have a tilted center of balance, so they are not easily rolled over. This was contriv ed through human ingenuity .
G	I was surprised that a sleeve of a Y-shirt nearly has the same shape created by diagonally cutting a cylinder.
H	I did not think that it would be a part of a wave-like shape (sine curve) when cut open.
I	Various shapes are used in daily li fe .
J	The head office of Fiji Television Network, Inc. has interesting shape s that includ e a quadrangular prism and a sphere.
K	There is the shape created by cutting a cylinder's top (frustum of a cone).
L	Let's draw it using Cabri 3D.