Addition and subtraction equations

Target: Solve an equation by subtracting the same amount from both sides.

Language target: Name the inverse operation.

Likely miss: Students add the constant that should be subtracted.

Ask: What did you do to both sides?

If you see it: Ask which move undoes the operation on x and do it on both sides.

Evidence to listen for: Both sides show the same inverse step.

Next: Return to the balance if only one side changes.

Observable student moves: names both quantities, uses the represented relationship, and revises after feedback. This companion is not a score.