Master Builder Prime · Level 2 · Term 1

Going the Distance

Build the Rhino. Crack the maths. Stop just before the wall.
Maths Robotics Hands-on
Rhino robot
Challenge: Going the Distance Maths
4

Today we will:

  • 1Build the Rhino.
  • 2Learn how to control the distance of motors with circumference.
  • 3Test different speeds and wheels to see how it affects our Rhino.
Ready, set… roll!
Rhino robot
New idea: Circumference Concept
4
Circumference The distance around the outside of a circle.

What it means

The distance around the outside of a circle is called the circumference.

You could measure it by wrapping a piece of string around the wheel and then measuring the string.

When a wheel makes one full rotation, it travels the distance of the circumference.

1 full rotation = 1 circumference
1 rotation
Activity 1 Building and Testing
5
  • Build the Rhino.
  • Place your Rhino one meter away from a wall.
  • Test your program.
Did the Rhino hit the wall? YESNO
  • Modify your code so the Rhino stops when its nose (the button) is pressed.
  • Test your new code to make sure it works.
Rhino approaching a wall
Activity 2 Calculations of Distance
5

How can we control the Rhino and stop it before it crashes?

  • Calculate how many wheel rotations the Rhino can make before it hits the wall.

To calculate wheel rotations, we need to know the distance and the circumference.

distance
÷
circumference
=
number of rotations
🚀 Ask your teacher for this number — or have them show you how to calculate it yourself!
  • Code your robot to move the correct number of rotations to stop just before the wall.
Rhino side view
Activity 3 Speed, Distance and Time
6
  • Change your code so it uses seconds, not rotations.
  • Choose four speeds to test. Work out how many seconds you'll need to stop just before the wall.
⏱️ Speed × Time = Distance
Speed (%)Seconds
Activity 4 Size matters?
6

Look in your box and test out as many different wheel options as you can.

Write down below how the testing went.

Things to think about

• Did bigger wheels travel further per rotation?

• Did smaller wheels grip better?

• What changed when you swapped wheels but kept the same code?

🔧 New wheels = new circumference!
Build 1: Rhino — Coding Guide Code
C1
Make it drive forwards a number of times.
when program starts
⚙ set movement motors to B+A
⚙ set movement speed to 50 %
⚙ move for 10 rotations
Drives forwards until we bump into something.
when program starts
⚙ set movement motors to B+A
⚙ set movement speed to 50 %
⚙ start moving
◎ wait until C is pressed
⚙ stop moving
Build 1: Rhino — Extension Challenges Stretch
C2
Sound Can you make the Rhino play a noise when it starts charging, or gets hit?
Rhino robot
Logic What can you add to your code to make it keep driving forwards and stop when bumped?
Build How could you change the Rhino so it can never be flipped over?
Sensor Can you add a colour sensor to control when the Rhino starts?
Lesson Complete

Great work, Master Builder!

You built the Rhino, used circumference to control distance, and tested how speed and wheel size change your robot's journey.

Build ✓ Maths ✓ Test ✓
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