Final answer:
To draw a double number line for a 2.1 ratio, create two parallel lines with a common zero point. Scale the first line by units of 2 and the second by units of 1 to represent the proportional relationship.
Step-by-step explanation:
How to Draw a Double Number Line
To represent a ratio of 2.1 using a double number line, you will essentially be creating two parallel number lines that correspond to each other. Here's a step-by-step process:
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- Draw two horizontal lines parallel to each other and of the same length.
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- Choose a starting point on each line to represent the zero point for both quantities in your ratio.
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- Along the top number line, indicate a scale for the first quantity. If you're using units, such as inches, start from zero and mark every unit with a corresponding increase of 2 in the ratio (e.g., 0, 2, 4, 6, etc.).
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- On the bottom number line, indicate a scale for the second quantity in the ratio, which increases by 1 for every 2 units on the top line (e.g., 0, 1, 2, 3, etc.). That way, for each point on the top line, there is a corresponding point on the bottom line that is half its value.
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- Remember to label the number lines with the appropriate units if they are given, such as inches or feet.
By following these steps, you create a visual representation of how each unit increase on one line corresponds to a 2.1 increase on the other.