Rounding - Texas Instruments TI-15 Teachers Manual

In the Range
Collecting and Organizing Data
As students are playing the game, focus their
attention on the patterns that are developing by
asking questions such as:
When you record a measurement, why is
rounding always involved?
When you read a measurement, what interval
should that measurement always indicate to
you? (½ a unit less or ½ a unit more)
How would this interval look on a number line
(or meter stick)?
How is ½ represented in the metric system?
How are you deciding how to represent the
range of possible measurements? What patterns
are you using?
Analyzing Data and Drawing Conclusions
To guide students in the analysis of their data, ask
questions such as:
What range is indicated by every measurement?
What patterns did you use in identifying the
range of possible measurements?
How would you use these patterns to round
256.0295 to the nearest tenth?
Continuing the Investigation
Have students replace the units of length with units
of mass (grams, centigrams) or capacity (liters,
milliliters) to notice the same patterns.
Have students discuss why this decimal place-value
approach with the calculator does not work for
measurements in yards, feet, and inches. Have them
identify what range a measurement would lie in if it
was measured to the nearest yard, nearest foot, and
nearest inch. (For example, 2 yards would lie
between 1 yard and 18 inches and 2 yards and 18
inches.)
© 2000 T I
EXAS NSTRUMENTS
(Continued)
I
NCORPORATED
TI-15: A Guide for Teachers
26