🔍 Key Concepts

• Chart scale ratios always compare a distance on the chart to the SAME UNIT of distance on the Earth • In a ratio like 1:5,000,000, the first number is the distance on the chart, the second is the distance on the Earth • Remember that chart scales are usually defined in the same units (e.g., inches to inches, centimeters to centimeters)

💭 Think About

• Ask yourself: In a scale written as 1:5,000,000, what does the "1" represent and what does the "5,000,000" represent? • Look carefully at which answers keep the same units on both sides of the ratio (for example, inches to inches). Which choices change units? • If you measured 1 inch on the chart, what would that represent on the Earth’s surface according to a 1:5,000,000 scale?

✅ Before You Answer

• Make sure the ratio compares same units to same units (e.g., inches to inches, cm to cm) • Check whether the answer option is keeping the meaning: first number = chart distance, second number = Earth distance • Eliminate any option that uses nautical miles in the ratio, because standard chart scales are not written that way