Question:The price of a laptop is $525. Alex paid a sales tax of 8% on the price. What is the...

1. TRANSLATE the problem information

• Given information:
  • Laptop price: \(\$525\)
  • Sales tax rate: \(8\%\)
  • Find: amount of sales tax (in dollars)

• What this tells us: We need to find \(8\%\) of \(\$525\)

2. INFER what we're calculating

• The question asks for the "sales tax amount" - this is the tax portion only, not the total price
• Sales tax is calculated as a percentage of the original price

3. TRANSLATE the percentage calculation

• "\(8\%\) of \(\$525\)" means: \(8\% \times \$525\)
• Convert percentage to decimal: \(8\% = 0.08\)
• Mathematical expression: \(0.08 \times 525\)

4. Calculate the result

• \(0.08 \times 525 = 42\)

Answer: 42

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak TRANSLATE skill: Students forget to convert the percentage to decimal form and calculate \(8 \times 525 = 4,200\) instead of \(0.08 \times 525 = 42\).

They see "\(8\%\)" and just use "8" in their calculation, forgetting that percentages must be converted to decimals for multiplication. This leads to an answer that's 100 times too large and doesn't make sense in context (the tax would be more than 7 times the laptop price!).

Second Most Common Error:

Poor INFER reasoning: Students misunderstand what the question is asking for and calculate the total amount paid (\(\$525\) + tax) instead of just the tax amount.

They correctly find that tax = \(0.08 \times 525 = 42\), but then add this to the original price: \(525 + 42 = 567\), thinking this is what the question wants. This causes them to provide 567 as their answer instead of 42.

The Bottom Line:

This problem tests whether students can properly TRANSLATE percentage language into mathematical operations. The calculation itself is straightforward once the setup is correct, but the percentage-to-decimal conversion is where many students stumble.