Understanding Scale and Proportions

This video lesson, part of Mr. Decatus' Math 7 series, covers scale drawings and models. It explains how to enlarge or reduce drawings proportionally, using maps as examples. The lesson demonstrates calculating actual distances using map scales and explores scale models of Earth's layers. It concludes with finding scale factors, emphasizing the importance of understanding proportions in real-world applications.

What is a scale drawing?

• A map of a city

• A three-dimensional model of an object

• A proportional two-dimensional drawing of an object

• A non-proportional drawing of an object

If a map scale is 1 inch equals 10 miles, what does this mean?

• 1 inch on the map represents 10 miles in reality

• 1 inch on the map represents 1 mile in reality

• 10 inches on the map represent 1 mile in reality

• 10 inches on the map represent 10 miles in reality

How far is it from Cadillac to Detroit as the crow flies if the map distance is 3.5 cm and the scale is 1 cm equals 50 miles?

• 175 miles

• 225 miles

• 150 miles

• 200 miles

What is the actual distance between Detroit and Marquette if the map distance is 7 cm and the scale is 1 cm equals 50 miles?

• 300 miles

• 450 miles

• 350 miles

• 400 miles

In a scale model of Earth's layers, if 1 inch represents 500 km, how thick is the liquid outer core if it is 2300 km in reality?

• 7.5 inches

• 5.2 inches

• 4.6 inches

• 6.0 inches

If a scale model has a scale of 1 inch to 500 km, what is the model's thickness if the actual thickness is 1000 km?

• 1 inch

• 4 inches

• 3 inches

• 2 inches

What is the scale factor if a model is 10 inches tall and the actual object is 100 feet tall?

• 1:120

• 1:10

• 1:150

• 1:100

How many inches are in 10 feet?

• 100 inches

• 110 inches

• 120 inches

• 130 inches

What does it mean when a scale factor is 1:120?

• The model and the actual object are the same size

• The actual object is 120 times larger than the model

• The model is 120 times larger than the actual object

• The model is 120 times smaller than the actual object

What is the purpose of using a scale in drawings and models?

• To create non-proportional representations

• To accurately represent the size of objects

• To simplify complex objects

• To make objects appear larger