1. The problem involves analyzing a Grade 4 learner's interpretation of the number sentence $$12 + 5 = \square + 8$$ and their incorrect working: $$12 + 5 = 17 + 8 = 25$$. 2. The learner's error is that they treated the equal sign as if it were a prompt to perform an operation and then write a total answer rather than understanding it as a symbol indicating equivalence between two expressions. 3. This shows a misconception about the equal sign; instead of recognizing it means "is equal to," they see it as a signal to write the answer or continue calculation on the right. 4. Among the given options, this matches option C: Interpreting the equal sign as a procedural marker ("answer"). Final answer: C