Map skills: scale, direction and distance
Geography · Key Stage 3 · The School
What a scale actually tells you
A scale of 1:25 000 means one centimetre on the paper is 25 000 centimetres on the ground — 250 metres. So four centimetres is a kilometre. The number is a ratio, not a unit, which is why the same map works whether you measure in centimetres or inches: it is always "this much on paper is that much on the ground".
Measuring a route that bends
A straight-line measurement between two villages underestimates every walk you will actually take. Lay a strip of paper along the road, marking each turn, then straighten the strip against the scale bar. A footpath measured straight might read 2 km and walk 3.2 km, and the difference is an hour of daylight.
Direction, said precisely
The eight-point compass runs north, north-east, east, south-east, south, south-west, west, north-west. Directions are given FROM the first place TO the second, and reversing them reverses the answer: if the church is north-east of the school, the school is south-west of the church. Grid north on an Ordnance Survey map is not quite magnetic north, and the margin tells you the difference.
Contours: height without a photograph
Contour lines join points of equal height, usually every ten metres. Lines close together mean a steep slope, lines far apart mean a gentle one, and a closed ring means a summit. That is the whole trick, and it lets you see from a flat sheet whether a route climbs — which no aerial photograph will tell you at a glance.