Sharp EL-531RH Teachers Manual page 32

Trial and Improvement
Switch FSE and TAB to normal display for further operation.
Press FSE until FIX, SCI, or ENG are not shown on the display.
• • • • • • • • • • • Using the activity in the classroom • • • • • • • • • • •
This activity may be given to students with little introduction or, with the use of the OHP unit, this
or a similar task may be introduced to the whole class followed by individual work on one or more
of the extension activities. The use of the multi-line playback function will be of practical benefit in
tackling questions involving trial and improvement.
• • • • • • • • • • • • • • • Points for students to discuss • • • • • • • • • • • • • •
It will be necessary to familiarize the students with the FSE and TAB keys in order to understand,
for example, why 4.641
similar problems, students will need to consider what degrees of accuracy are appropriate; in the
case of cubic centimeters of ice cream, possibly only to one decimal place.
Further Ideas
• Find the side of a cubical carton whose volume is 1/2 liter. It may be necessary to remind
students of the equivalence of 500 ml (fluid measure) and 500 cm
• Find the dimensions of a fruit juice carton whose sides are in the proportion 1 : 2 : 3 and
whose capacity is 1 liter.
• Find the Golden Ratio x by trial and improvement of the relation
Guess x (Guess + 1) = 1
Use the playback function on the calculator to show that
x = 1 / (1 + x) and that x =
All metric paper has the same shape (except golden). If A0 has an area of 1 m
side is times bigger than the smaller side, find these dimensions. What are the dimensions
of A4? Have the students confirm their calculations by measuring a sheet.
3 3
both have the value 100 to the nearest unit. In the context of
and 4.642
.
31
Junior high school
DEG
3
(solid measure).
2
and the longer