Grade Level/ Course (HS): 8th Grade
Standard
with code:
Domain:
8.NS.2 Use rational approximations of irrational numbers to compare the size of irrational numbers, locate them
approximately on a number line diagram, and estimate the value of expressions (e.g.,  2 ). For example, by
truncating the decimal expansion of 2 , show that 2 is between 1 and 2, then between 1.4 and 1.5, and explain
how to continue on to get better approximations.
The Number System
Cluster:
Know that there are numbers that are not rational, and approximate them by rational numbers.
Type: ______Knowledge
___X___Reasoning
______Performance Skill
______Product
Knowledge Targets
Reasoning Targets
Performance Skills
Targets
Approximate irrational numbers as
rational numbers.
Compare the size of irrational numbers using
rational approximations.
Product Targets
Approximately locate irrational
numbers on a number line.
Estimate the value of expressions
involving irrational numbers using
rational approximations. (For
example, by truncating the decimal
expansion of 2 , show that 2 is
between 1 and 2, then between 1.4
and 1.5, and explain how to continue
on to get better approximations.)
Make sense of
problems and
persevere in
solving them.
Reason abstractly
and quantitatively.
Construct viable
arguments and
critique the
reasoning of
others.
Model with
mathematics.
Use appropriate
tools strategically.
Attend to
precision.
Look for and make
use of structure.
Look for and
express regularity
in repeated
reasoning.
Copyright © 2011 Kentucky Department of Education
The content of this document constitutes original works of authorship owned by the Kentucky Department of Education (KDE) and may not be reproduced without
the express, written permission of the KDE.