1) Ratios within the Class. NCTM Addenda Series.

Date: Fri, 24 Jan 1997 12:39:03 -0600 (CST)
From: "Peter J. Smith" 
Sender: "Peter J. Smith" 
Reply-To: "Peter J. Smith" 
Subject: Re: Teaching Ratio and Proportion
To: Debbie Bloom 
Mime-Version: 1.0

Debbie,
I agree that ratio and proportion are powerful tools. I use it to solve 
percent problems, and any other situations that lend themselves to 
proportions. Some suggestions for using proportions could include finding 
ratios within your class (such as the number that wear glasses, are 
left-handed, have a certain number or type of pet,...), and then using 
proportions to predict how many students in the entire school or grade 
share the characteristic. Another application is in model cars, planes, 
boats, trains, etc. Use the scale given on the model and with the help of 
proportions, determine the actual size of the car in rela life. Perhaps 
even building a real life-size part would help bring this concept to 
life. You should also look for the NCTM Addenda Series: Measurement in 
the Middle Grades, Geometry and Spatial Sense, and Geometry in the Middle 
Grades. Good Luck!

                  ###########################################         
          
			Peter Smith
			Supervisor of Mathematics
			Omaha Public Schools
			3215 Cuming Street
			Omaha, NE 68131
			(402) 557-2442
			psmith@ops.esu19.k12.ne.us
	
	"Mathematics seems to endow one with something like a new sense.
						-Charles Darwin

2) Measure Desks and Use 1:n to Compare Order of Ratios

Date: Sat, 25 Jan 1997 07:00:47 +0800
From: Wong Khoon Yoong 
To: Debbie Bloom 
Subject: Re: Teaching Ratio and Proportion

You have an extensive set of activities. Precisely what do they find
difficulty with scales on maps? Is it because the numbers are not 'nice' or
too big?

I get pupils to measure the length and width of their desk and express it in
the 1:n form. This is a transition from ratios of discrete quantities
(number of boys to girls type) to continuous quantities. Use the 1:n form to
compare the order of ratios.
With best wishes!

------------------------------------------------
Wong Khoon Yoong
Department of Science and Mathematics Education
Sultan Hassanal Bolkiah Institute of Education
Universiti Brunei Darussalam
Bandar Seri Begawan 2028
BRUNEI DARUSSALAM