In this activity students recall the notation for absolute value presented in grade 6 by explaining the meaning of absolute values in a situation and then comparing values using absolute value. Students reason abstractly and quantitatively when interpreting the meaning of absolute value (MP2). In the associated Algebra 1 lesson, students build on the understanding from grade 6 by thinking of the absolute value function as a piecewise function.

The purpose of the discussion is for students to recall their understanding of absolute value and its meaning in context. Here are some questions for discussion:

• “What does the equation tell you?” (It tells me that -4 is 4 away from 0 on the number line.)
• “Clare is complaining that she cannot pay off her credit card this month. When you ask why, she replies with . How do you think this inequality makes sense as a reason?” (It probably means that Clare owes $245 on her credit card, but has only $175. Since the amount owed on the credit card is greater than the amount of money she has, she cannot pay off the credit card.)
• “Is the rule a function? Explain your reasoning.” (Yes, because each input has exactly 1 output.)
• “Mai wants to write the meaning of absolute value in some notes and writes . Is this equation true for every value of ?” (No. If is negative, this is not true. For example, is not a true equation.)

In this activity, students get more familiar with how to use the absolute value by reviewing its place in order of operations. In the associated Algebra 1 lesson, students examine absolute value as a piecewise function. This activity helps familiarize students with absolute value as an operation before they understand it as a function.

In this activity, students critique a statement or response that is intentionally unclear, incorrect, or incomplete and improve it by clarifying meaning, correcting errors, and adding details (MP3).

The purpose of the discussion is to gain familiarity with absolute value as an operation.

Use Critique, Correct, Clarify to give students an opportunity to improve a sample written response to the first question by correcting errors, clarifying meaning, and adding details.

• Display this first draft:
  Absolute value makes everything positive, so .
  Ask, “What parts of this response are unclear, incorrect, or incomplete?” As students respond, annotate the display with 2–3 ideas to indicate the parts of the writing that could use improvement.
• Give students 2–4 minutes to work with a partner to revise the first draft.

Select 1–2 students or groups to slowly read aloud their draft. Record for all to see as each draft is shared. Then invite the whole class to contribute additional language and edits to make the final draft even more clear and more convincing.

After Critique, Correct, Clarify, select students to share their process and solutions for the remaining problems.