Question

for each line, you are asked to click in a box of a given length on the line. when you click one asked for will appear.
if you decide that the box you clicked on is not the correct length, click in the box again it disappear, then, click in the box that you think is correct.

click in the box with the blue arrow pointing to 1 kilometer on this line

0 1/2 mi 1 mi 1 1/2 mi 2 mi 2 1/2 mi

click in the box with the blue arrow pointing to 1 mile on this line:

0 1/2 km 1 km 1 1/2 km 2 km

click in the box with the blue arrow pointing to 500 meters on this line:

0 1/2 km 1 km 1 1/2 km 2 km 2 1/2 km

Explanation:

Step1: Convert 1 km to miles

We know $1 \text{ km} \approx 0.621 \text{ mi}$, which is between $0.5 \text{ mi}$ and $1 \text{ mi}$, closer to $0.5 \text{ mi}$.

Step2: Convert 1 mile to km

We know $1 \text{ mi} \approx 1.609 \text{ km}$, which is between $1 \text{ km}$ and $1.5 \text{ km}$, closer to $1.5 \text{ km}$.

Step3: Convert 500 meters to km

$500 \text{ m} = \frac{500}{1000} \text{ km} = 0.5 \text{ km}$

Answer:

1. For 1 kilometer: Click the box above the position between $1/2 \text{ mi}$ and $1 \text{ mi}$ (closer to $1/2 \text{ mi}$)
2. For 1 mile: Click the box above the position between $1 \text{ km}$ and $1\ 1/2 \text{ km}$ (closer to $1\ 1/2 \text{ km}$)
3. For 500 meters: Click the box above the $1/2 \text{ km}$ mark