Measuring scale on OS Maps
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Transcript of Measuring scale on OS Maps
Lesson objectives:
Knowledge:
All will understand what we mean by scale
Most will explain how to covert it into real world distance
Some will explain the technique to measure a curved line on a map
Skills:
All will be able measure straight line distances on a map and covert them into ‘real world’ distance
Most will be able to measure curved distances (roads & rivers) and convert them into ‘real world’ distance
Keywords for today's lesson:
Scale
Distance
Kilometres (KM)
Centimetres (CM)
Measuring
Accuracy
Why do we use scale?
When we make a map … we shrink the real world so that it can fit on a page
We use scale to do this…
Simply put, scale is how much the person making the map has shrunk the real world
So how does it work?
Simply put, scale is how much the person making the map has shrunk the real world
1cm on the map 4km in the real world
0 1 2 3 4 5 6Kilometres
2cm = 1km
You can measure the distance in cm
Try to be exact!
(Each extra mm = .1)
Then … divide by 2 to change to km
4cm = 1km
You can measure the distance in cm
Try to be exact!
(Each extra mm = .1)
Then … divide by 4 to change to km
Convert these scales
Scale 2cm = 1 km
1) 2cm
2) 4cm
3) 6cm
4) 7cm
5) 5cm
Scale 4cm = 1 km
1) 4cm
2) 2cm
3) 6cm
4) 7cm
5) 5cm
Quick recap
Answers
Scale 2cm = 1 km
1) 1km
2) 2km
3) 3km
4) 3.5km
5) 2.5km
Scale 4cm = 1 km
1) 1km
2) 0.5 km
3) 1.5km
4) 1.75 km
5) 1.25 km
Quick recap
How do we measure something that isn’t straight?
Things like roads and rivers are bendy, but our ruler is straight…
How can we measure them?
How do we measure something that isn’t straight?
Step forward our hero
Activity
We are going to measure the distances between points on your map using the ‘magic strip’ technique we have just watched
You need:-Your ruler-Pencil-Your ‘Magic strip’
Have we met our lesson objectives?
Knowledge:
All will understand what we mean by scale
Most will explain how to covert it into real world distance
Some will explain the technique to measure a curved line on a map
Skills:
All will be able measure straight line distances on a map and covert them into ‘real world’ distance
Most will be able to measure curved distances (roads & rivers) and convert them into ‘real world’ distance