standard_description: Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number.
problem_activity: Problem 1
Simplify
$${\sqrt{8}+5\sqrt{2}}$$
.
Problem 2
Write a radical addition or subtraction problem that cannot be simplified, and explain why it cannot be simplified.


aligns: no