Rita's total bill at a restaurant was $25.00, including tax. If she left a tip of 20% of the total...

1. TRANSLATE the problem information

• Given information:
  • Total bill: $25.00 (including tax)
  • Tip rate: 20% of the total bill
  • Find: Amount of the tip

2. TRANSLATE the percentage to decimal form

• Convert 20% to decimal: \(20\% = \frac{20}{100} = 0.20\)
• This allows us to multiply directly

3. Calculate the tip amount

• Tip = \(0.20 \times \$25.00 = \$5.00\)

Answer: D. $5.00

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak TRANSLATE skill: Misreading the percentage in the problem statement

Students might accidentally misread "20%" as "14%", "16%", or "18%" due to hasty reading or visual confusion with the digit shapes. When they perform the calculation correctly but with the wrong percentage:

• 14% of $25 = \(0.14 \times 25 = \$3.50\)
• 16% of $25 = \(0.16 \times 25 = \$4.00\)
• 18% of $25 = \(0.18 \times 25 = \$4.50\)

This may lead them to select Choice A ($3.50), Choice B ($4.00), or Choice C ($4.50).

The Bottom Line:

This problem tests careful reading and basic percentage-to-decimal conversion. The key is accurately identifying that the tip rate is exactly 20%, then converting this to 0.20 for the multiplication.