Scale and Proportional Animals

Name:

Date:

Overview and Warm-up

This 3-day project helps you practise scale and proportional thinking by enlarging and reducing animals. Use measurements in centimetres (cm) and metres (m), and show all working in the boxes provided.

1. A toy kangaroo model measures 14 cm from nose to tail and is a 1:40 scale model. How long is the real kangaroo in metres? Show your working.

2. A giraffe is 5.4 m tall. You will draw a classroom model at a scale of 1:18. What height (in cm) should your model be? Show your working.

3. A frog drawing is reduced by a scale factor of 1:3. If the original frog is 9 cm long, how long is the reduced frog? Write the scale factor as a fraction and as a decimal.

Day 1 → Day 3: Practical Tasks

4. Day 1 — Measure and enlarge (Practical)

a) Choose an animal (photo or toy) and record two measurements: length (nose to tail) ______ cm and height (ground to highest point) ______ cm.

b) Enlarge your animal by a scale factor of 2. Calculate the new length and new height (show working).

c) Sketch the enlarged animal to the best of your ability and label the new dimensions.

5. Day 2 — Design a small scale model

Create a tabletop model at scale 1:50 using your Day 1 measurements. Calculate the model measurements in centimetres and millimetres. Show working for both length and height.

6. Day 3 — Proportions, area and volume

a) If the linear dimensions of an animal are increased by a factor of 1.8, by what factor does surface area change? By what factor does volume change? Show working.

b) If the real animal's mass is 80 kg and mass scales with volume, estimate the new mass after enlargement by 1.8. Show working and give your answer in kg (to one decimal place).

Reflection and Extension

7. Match the description to the correct scale factor.

A. Model is half the size of the real animal

B. Drawing enlarged to twice the linear size

C. Model is 1/100 of real size

1. 1:2

2. 1:50

3. 1:100

8. Short reflection: What was the most challenging part of using scale and proportional reasoning in this project? How did you solve or attempt to solve it?

9. Extension challenge (optional): Choose one animal and explain in one paragraph how changing linear scale would affect its appearance, strength (approx.), and estimated mass. Include at least one calculation to support your idea.