Marcus is packing for a trip and his suitcase has a maximum weight limit of 50 pounds. His current packed...

1. TRANSLATE the problem information

• Given information:
  • Maximum weight limit: 50 pounds
  • Current weight of packed items: 37 pounds
  • Need to find: maximum additional weight

2. INFER the mathematical relationship

• To find remaining capacity, subtract what's already used from the total limit
• Maximum additional weight = Total limit - Current weight
• Set up the calculation: \(50 - 37\)

3. Calculate the result

\(50 - 37 = 13\) pounds

Answer: A. 13

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak TRANSLATE skill: Students misinterpret what "maximum additional weight" means and think it refers to the total weight Marcus can pack, rather than the remaining capacity.

This leads them to select Choice C (50), thinking the answer is simply the weight limit itself.

Second Most Common Error:

Conceptual confusion about the relationship: Some students add the current weight to the limit instead of subtracting, thinking "additional" means "add more to what we have."

This may lead them to select Choice D (87) by calculating \(50 + 37 = 87\).

The Bottom Line:

This problem tests whether students understand that "remaining capacity" requires subtraction, not addition. The key insight is recognizing that Marcus can only add weight up to the unused portion of his limit.