Explaining Rounding Using a Number Line

Date: 7/29/96 at 13:36:9
From: Anonymous
Subject: Alternative Methods for Teaching Rounding

What is the best way to introduce and explain the term "rounding" to 
a student who speaks limited English, in our case Spanish? Right now 
we try to demonstrate the concept, but we would like to explain the 
term for better understanding.

Date: 8/4/96 at 17:1:17
From: Doctor Jerry
Subject: Re: Alternative Methods for Teaching Rounding

Perhaps you could try a graphical/visual approach. If, for example, we 
are asked to round  the positive number 13.492 to the nearest tenth, 
then draw a number line with the numbers 11, 12, 13, 14, 15 marked.  
The number 13.492 will lie between 13 and 14.  In the interval from 13 
to 14, mark the tenths, that is, mark 13.0, 13.1, 13.2, . . . , 13.9, 
14.0.  The number 13.492 lies between the marks for 13.4 and 13.5.  
Since it is closer to 13.5 than to 13.4, the answer to the question 
(round 13.492 to the nearest tenth) is 13.5.  

It seems to me that this gets around the language question about as 
well as possible.

-Doctor Jerry,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/