Sharp EL-531RH, Teachers Manual

Page: 8 / 56

7
Junior high school
Down to One
• • • • • • • • • • • Using the activity in the classroom • • • • • • • • • • •
Students should be encouraged to estimate the results of calculations and think about the appro-
priate operations and numbers to use during the game. Let’s start with 864, for example. This
number is divisible by 9, 6, 3 and 2. The equation 846
÷
9 could therefore be a possible first step.
This will prompt students to test the divisibility of numbers. Students should also be encouraged to
think about the various strategies they use.
The game could be played between small group of students.
• • • • • • • • • • • • • • • Points for students to discuss • • • • • • • • • • • • • •
For some students, it may be more appropriate to start with a 2-digit number. In this case, the calcula-
tor should be set to fixed decimal place mode by pressing the [2ndF] key once and then pressing the
[ . ] key, which has FSE written in yellow above it, until FIX is displayed at the top of the calculator
screen. And press [2ndF] [TAB] and [0] keys. Doing this will round answers to 0 decimal places. The
starting number can then be generated by multiplying a random number by
1
00.
Further Ideas
• Play the game using decimal starting numbers.
• Give the students a shuffled set of cards numbered from
1 to 9 and a shuffled set of
cards numbered
1
0, 20, 30, 40, 50. Students choose five cards from the first set, and
two cards from the second set. The calculator is then used to generate a random three
digit integer, and the students have to make this total by using the numbers on the cards.
Example B:
You want to subtract 8 from 9, but you cannot since you have already used 8 once.
So...
The calculator displays 1 and the game is finished.
9
8
3
2