standard_description: Write simple expressions that record calculations with numbers, and interpret numerical expressions without evaluating them. For example, express the calculation “add 8 and 7, then multiply by 2” as 2 × (8 + 7). Recognize that 3 × (18932 + 921) is three times as large as 18932 + 921, without having to calculate the indicated sum or product.
problem_activity: Task
Consider the algebraic expressions below:
$$ (n + 2)^2 - 4 \qquad \text{and} \qquad n^2 + 4n. $$
Use the figures below to illustrate why the expressions are equivalent:
[IMG]
Find some ways to algebraically verify the same result.


aligns: no