Grid References, Scale & Distance Flashcards

All 6 cards in this deck

What is the map scale on a map?

The ratio of a distance on the map to the actual distance on the ground, e.g. 1:50 000.

On an OS map, what are eastings and northings?

Eastings are the vertical grid lines, increasing in value eastwards; northings are the horizontal grid lines, increasing in value northwards.

What are the steps to give a four-figure grid reference?

e.g. a square whose bottom-left corner is easting 09, northing 28

1. Read the easting of the bottom-left corner of the square: 09
2. Read the northing of the bottom-left corner: 28
3. Write easting then northing: 0928

What are the steps to give a six-figure grid reference?

e.g. a point 8 tenths across and 2 tenths up in square 0928

1. Take the four-figure reference: 09 and 28
2. Add tenths across the square to the easting: 098
3. Add tenths up the square to the northing: 282, giving 098282

How do you measure a curved distance, such as a road, on an OS map?

e.g. along the A944 between two junctions

1. Lay string or the edge of paper along the curve, marking each bend.
2. Straighten it against the linear scale bar.
3. Read off the ground distance, e.g. 3.8 km

True or false? A 1:25 000 OS map shows a smaller area in more detail than a 1:50 000 OS map.

True. At 1:25 000 features are drawn twice as large, so less ground is covered but with more detail.