Standard: 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., π2). 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.
Approximations of Irrational Numbers
Vocabulary for this standard: irrational numbers, approximation
EngageNY lesson link – This appears in the second part of the module dealing with making converting fractions and decimals.
Quick thoughts: This is a pretty easily understood standalone concept that gets obfuscated somewhat by the module in the EngageNY curriculum.
An irrational number is a number that cannot be written as a ratio of two integers.
An approximation is an estimate or figure that is not intended to be exact.