Page 200 - NUMINO TG_6A
P. 200
13Scale Down, Scale Up Unit
Material Ruler
Objective: Use proportions to find the measurements of similar figures
Is the bridge actually drawn as 30 m? Measure the length of the bridge across Have student volunteers use the ruler to
measure the length of the bridge on the map
the mud with a ruler. (2 cm).
How many meters on the map does 1 cm
What you need: Ruler represent? 15 meters, because a 30 meter
bridge is 2 cm long on the map.
How many meters does 1 cm on the map represent? scale actual distance
15 meters is drawn as 1 cm on the map. scale distance
Chat Have students form groups to determine the
distance to the Treasure Castle, based on
The distance from where the children are to the Treasure Castle on the the map. Distance should be measured
map is approximately 30 cm. Find the actual distance to the Castle in along the path, not in a straight line.
meters. Afterwards, discuss how you found the distance.
Measurement along the path shows that the
Students should use proportion to find the actual distance. Have them figure this problem distance to Treasure Castle is about 30 cm,
out on their own or discuss with their classmates. corresponding to a scale distance of about
450 meters. Note that there are variant
The distance from where the children are to the Treasure Castle on the methods of computing this, all based on
map is approximately 30 cm. The actual distance in meters can be converting measured to scaled distances.
found by forming a proportion.
distance on the map 2 cm = 30 cm
actual distance 30 m a m
2 a = 30 30
a = 450 m
So, the actual distance to the Treasure Castle is 450 meters.
13. Scale Down, Scale Up 109
No scale or ruler is strictly needed in order to convert map distances into real distances, just a pencil and
straight edge. We know that the length of the bridge is 30 meters, so if we mark each end of the bridge on a
straight edge, we know that this distance corresponds to 30 meters on the scale of the map, and we can
measure the map in units of 30 meters.
6A Unit 13 183
Material Ruler
Objective: Use proportions to find the measurements of similar figures
Is the bridge actually drawn as 30 m? Measure the length of the bridge across Have student volunteers use the ruler to
measure the length of the bridge on the map
the mud with a ruler. (2 cm).
How many meters on the map does 1 cm
What you need: Ruler represent? 15 meters, because a 30 meter
bridge is 2 cm long on the map.
How many meters does 1 cm on the map represent? scale actual distance
15 meters is drawn as 1 cm on the map. scale distance
Chat Have students form groups to determine the
distance to the Treasure Castle, based on
The distance from where the children are to the Treasure Castle on the the map. Distance should be measured
map is approximately 30 cm. Find the actual distance to the Castle in along the path, not in a straight line.
meters. Afterwards, discuss how you found the distance.
Measurement along the path shows that the
Students should use proportion to find the actual distance. Have them figure this problem distance to Treasure Castle is about 30 cm,
out on their own or discuss with their classmates. corresponding to a scale distance of about
450 meters. Note that there are variant
The distance from where the children are to the Treasure Castle on the methods of computing this, all based on
map is approximately 30 cm. The actual distance in meters can be converting measured to scaled distances.
found by forming a proportion.
distance on the map 2 cm = 30 cm
actual distance 30 m a m
2 a = 30 30
a = 450 m
So, the actual distance to the Treasure Castle is 450 meters.
13. Scale Down, Scale Up 109
No scale or ruler is strictly needed in order to convert map distances into real distances, just a pencil and
straight edge. We know that the length of the bridge is 30 meters, so if we mark each end of the bridge on a
straight edge, we know that this distance corresponds to 30 meters on the scale of the map, and we can
measure the map in units of 30 meters.
6A Unit 13 183
