To make a bakery's signature chocolate muffins, a baker needs 2.5 ounces of chocolate for each muffin. How many pounds...

1. TRANSLATE the problem information

• Given information:
  • 2.5 ounces of chocolate needed per muffin
  • Making 48 muffins total
  • Need final answer in pounds
  • Conversion factor: \(1\text{ pound} = 16\text{ ounces}\)

• What this tells us: We need to find total ounces first, then convert to pounds

2. INFER the solution strategy

• This is a two-step problem:
  • First: Calculate total ounces needed (rate × quantity)
  • Second: Convert ounces to pounds using the given conversion factor
• The key insight is recognizing that we can't stop after finding ounces - we must convert to pounds

3. Calculate total ounces needed

• Total ounces = \(48\text{ muffins} \times 2.5\text{ ounces per muffin} = 120\text{ ounces}\)

4. SIMPLIFY by converting to pounds

• Since \(1\text{ pound} = 16\text{ ounces}\), divide the total ounces by 16:
• Pounds needed = \(120\text{ ounces} \div 16\text{ ounces per pound} = 7.5\text{ pounds}\)

Answer: A. 7.5

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak INFER skill: Students correctly calculate the total ounces (120) but fail to recognize they need to convert to pounds. They see 120 ounces as their final answer and don't notice the question asks for pounds.

This leads them to select Choice D (120) without completing the conversion step.

Second Most Common Error:

Poor TRANSLATE reasoning: Students misunderstand the conversion relationship, either using the wrong conversion factor (dividing by something other than 16) or applying the conversion in the wrong direction (multiplying by 16 instead of dividing).

This calculation error can lead to confusion and guessing among the remaining choices.

The Bottom Line:

Multi-step word problems require careful attention to units throughout the solution. The key is recognizing when you have an intermediate result (ounces) versus the final answer format requested (pounds).