Scale 4 inches : 1 mile

But 2640 yards is not a round number. Select a round number of 3000 yards.

1760 yards are represented by = 4 inches

3000 yards are represented by

Construction : Draw a line 6.8 inches long. Divide it into 6 equal parts each showing 500 yards. Sub-divide the left hand part into 5 equal divisions. Each will show 100 yards.

The scale of the map is 1 cm = 1 km. or 1 cm 100,000 cm since 1 km = 1,00.000 cm.