A Drive through the Zoo: Learning about Angles using Pro-Bot

My child's class started learning about angles about a week ago. And the teacher requested me to design an exercise for Pro-Bot that will introduce the idea of angles. As the kids are very new to the concept, I wanted to keep this one fairly simple, while still using a mix of acute, obtuse and right angles.

A trip to the zoo is almost always part of our field trips every school year. The zoo in our city happens to have buses that drive along the various points of interest/ themed animal enclosures. I felt that the turns made by the bus in this familiar setting of the zoo, might be a good way to introduce angles.

In this exercise, a scaled down version of the bus route, provides the path for Pro-Bot to drive on. As the Bot drives along the path, it is required to make angular turns at each point. I have provided the angular measurements required in degrees and distances in centimeters. The bus travels in a loop, the directions are shown using arrows. Note that the map below is not drawn to scale.

Based on the above map, write a program for Pro-Bot to drive along the following paths, assuming that the Pro-Bot is facing in the forward direction:

1. The path from the Entrance of the zoo to the African Savanah. How many turns did the Pro-Bot make? Were the angles acute, obtuse or right angles?
2. To continue from the African Savanah (where you stopped before), to the Elephants enclosure, how many degrees did the Pro-Bot turn? 
3. Program the path from the African Savanah to the Raptors. How many turns did the Pro-Bot make? Were the angles acute, obtuse or right angles?
4. Continue the path from the Raptors to the Kids' Play Area. Did you use acute, obtuse or right angles for the turns?

Alternatively, the kids can be asked to program the entire bus route as a single program, marking the types of angles used along the way.

A Follow-up Exercise to Drawing Digital Numbers using Pro-Bot

The following set of questions is a follow-up to drawing digital numbers using Pro-Bot. Rather than draw every number from 0 through 9, these questions allow the students to draw just a sub-set of the numbers. This is how I plan to use it with my students: Write out one or two of the following questions each on chits and let the kids pick the chits randomly. This way, everyone gets to work on a different problem and it allows for a bit of math practice as well.

1. Use Pro-Bot to draw the odd numbers from 0 to 9 according to the dimensions given in the figure.
2. Use Pro-Bot to draw the even numbers from 0 to 9 according to the dimensions given in the figure.
3. Use Pro-Bot to draw the missing number in the following pattern: 0, 3, ___ , 9, 12
4. Use Pro-Bot to draw the missing numbers in the following pattern: 13, 11, ___ , 7, ___, 3
5. Use Pro-Bot to draw the numbers that are multiples of 3 in the group 0 to 9.
6. Use Pro-Bot to draw the numbers that are divisors of 8 in the group 0 to 9.
7. Use Pro-Bot to draw the number that you get as the result of the problem 2 x 2 x 2 = ?
8. The sum of 2 numbers is 5. One of the numbers is one more than the other. Use Pro-Bot to draw the two numbers according to the dimensions given.
9. The difference between two numbers is 3. The sum of the two numbers is same as 5 x 3. Can you identify the numbers? Draw the numbers using Pro-Bot according to the dimensions given below.
10. If your birthday is a single digit number, draw it using Pro-Bot with the dimensions given below. Else, add up the digits in your birthday and draw that number using Pro-Bot.
11. Use Pro-Bot to draw the prime numbers in the group 0 to 9. A prime number is a number greater than 1, that can be divided only by 1 and the number itself. It does not have any other divisors.

All measurements in the figure below are in centimeters. 

Here is a set of programs for drawing the various numbers.

Solutions: Drawing Polygons using Pro-Bot

Here is a subset of the possible solutions for drawing the polygons in this assignment. Please keep in mind that there are multiple correct ways of programming each of these figures.


The following programs draw the polygons without using Repeat Loops.

1. Square of sides 8 cm:

Fd 8
Rt
Fd 8
Rt
Fd 8
Rt
Fd 8

2. Rectangle 4 cm x 6 cm: 

Fd 4
Rt
Fd 6
Rt
Fd 4
Rt
Fd 6

3. Parallelogram 4 cm x 6 cm:

Fd 4
Rt 45
Fd 6
Rt 135
Fd 4
Rt 65
Fd 6

4. Rhombus 6 cm:

Fd 6
Rt 60
Fd 6
Rt 120
Fd 6
Rt 60
Fd 6

5. Equilateral Triangle of sides 6 cm:

Fd 6
Rt 120
Fd 6
Rt 120
Fd 6 

6. Right Triangle of sides 3 cm, 4 cm, 5 cm:

Fd 3
Rt 126
Fd 5
Rt 144
Fd 4 

Drawing Regular Polygons using Repeat Loops in Pro-Bot

All of the regular polygons below have sides of 6 cm.

1. Equilateral Triangle

Rpt 3 [
Fd 6
Rt 120
]

2.  Square

Rpt 4 [
Fd 6
Rt 90
] 

// You can also use the instruction "Rt", instead of "Rt 90" in the code above,                                           // as the default turn is 90 degrees for Pro-Bot.

3. Pentagon

Rpt 5 [
Fd 6
Rt 72
]

4. Hexagon

Rpt 6 [
Fd 6
Rt 60
]

5. Octagon

Rpt 8 [
Fd 6
Rt 45
]

6. Nonagon

Rpt 9 [
Fd 6
Rt 40
] 

7. Decagon

Rpt 10 [
Fd 6
Rt 36
]

A Circle using a Repeat Loop

Rpt 360 [
Fd 1                 // Move 1 cm
Rt 1                 // Turn 1 degree
]

An Algorithm for Drawing Regular Polygons using Repeat Loops 

From the pieces of code above for various regular polygons, the relation between the number of sides of a regular polygon and the angle of turn can be deduced to 360/N where N is the number of sides of the polygon.

The generalized algorithm for drawing regular polygons is:

Rpt N [
Fd X
Rt 360/N
]

where N is the number of sides of the regular polygon, X is the length of each side of the polygon.  

Solutions: Art with Pro-Bot - A Soccer Game

The soccer game picture is a follow-up to the "Art with Pro-Bot: A Dancing Robot" exercise, with one of the figures being the exact same as the Dancing Robot and the other being its mirror image.

Let's name the figure on the left as Team A and the one on the right as Team B. You would recognize from the figure that both Team A and Team B share some parts in common, such as the head and the neck. So, it's easier for the programmer to write the code for these parts just once and store it as a procedure; it can then be used multiple times. 

// Proc 1 - procedure for the neck and head

Fd 1

Lt

Fd 1

Rt

Rpt 3 [

Fd 2

Rt

]

Fd 1

Team A:  

// Program written in Main and using the above procedure. The Start point is marked in the figure.

Rpt 4 [

Fd 10

Bk 4

Rt

]

Fd 3

Lt

Proc 1

Team B:

// Program written in Main and using the above procedure. The Start point is marked in the figure.

Rpt 4 [

Fd 10

Bk 4

Lt

]

Fd 3

Rt

Proc 1

Art with Pro-Bot: A Soccer Game

Let’s use Pro-Bot to draw a picture of robots playing soccer.

We shall work using both Repeat Loops and Procedures in Pro-Bot for this assignment. This "art" project was designed to use the concepts of Repeat Loops and Procedures in a fun way.

There are 2 robots in the picture, one representing Team 1 and the other, Team 2. The two robots are playing each other in a game of soccer. The dimensions are as follows: Each robot's body is a 6 cm side square, the limbs are 4 cm long, the neck is 1 cm long and the head is a 2 cm side square. 

While writing the programs for Pro-Bot to draw the figures, remember to use Repeat Loops for patterns that repeat. You can also see from the pictures that the head and neck is exactly the same for both pictures. Hence, you can write the program for the head and neck once, store it as a procedure in Pro-Bot's memory and call it for drawing both robots. 

Click here for a set of solutions.

Draw in as many members for each team as you like. You can even store the programs for each robot as separate procedures which makes it easier for you to draw multiple figures in your art project. You can put in a background of your choice and draw a soccer ball in the middle once you have drawn both teams. It does not have to be just soccer; students in my class have used this theme to depict scenes from various sporting events. We worked on this project the day after a major basketball game and there were quite a few children who made pictures with basketball scenes... Let your imagination run free in creating your art work. 

Solutions: Debugging

1.  The program to trace the number 2 has bugs in instructions & data.

   Fd 6
   Rt
   Fd 6
   Rt
   Fd 6
   Rt          //Wrong instruction, Rt instead of Lt
   Fd 6
   Lt
   Fd 12    //Wrong data, 12 cm instead of 6 cm

Here is the program with the bugs fixed:

   Fd 6
   Rt
   Fd 6
   Rt
   Fd 6
   Lt      
   Fd 6
   Lt
   Fd 6  




2.  The missing square bracket for the Rpt instruction is a very common bug.

    Rpt 2 [
    Fd 6
    Lt
    Rpt 3 [
    Fd 6
    Rt
    ]
    Rt
    Rt
    // The closing square bracket is missing as the last instruction here.
    // Without it, the outer loop executes only once, not twice as intended.


Here is the program with the bugs fixed:

    Rpt 2 [

    Fd 6
    Lt
    Rpt 3 [
    Fd 6
    Rt
    ]
    Rt
    Rt
    ]



3.  A stack of squares, using a Nested Loop:  The given program has bugs in data, punctuation (missing square bracket) and missing instructions.

    Rpt 2 [     // Wrong data, need 3 squares not 2
    Rpt 5 [
    Fd 6
    Rt
    ]
    // Missing a few instructions here, as well as a closing square bracket for the outer loop.


Here is the program with the bugs fixed:

    Rpt 3 [  
    Rpt 5 [
    Fd 6
    Rt
    ]
    Fd 6
    Lt
    ]

4.  A square of sides 6 cm divided into two equal parts: The given program has wrong data and wrong instructions.
   

    Rpt 4 [
    Fd 6

    Rt

    ]
    Fd 2     // Wrong data, need to move 3 cm to get to the midpoint 
    Rt
    Bk 6    // Wrong instruction, need Fd 6

Here is the program with the bugs fixed:
    Rpt 4 [

    Fd 6

    Rt

    ]
    Fd 3     
    Rt
    Fd 6    



5.  Three squares stacked on top of each other. 

    Rpt 2 [     // Wrong data: need 3 squares, so repeat 3
    Rpt 5 [

    Fd 6

    Rt

    ]

    // Missing instructions here

    ]

Here is the program with the bugs fixed:

    Rpt 3 [     
    Rpt 5 [

    Fd 6

    Rt

    ]

    Lt
    ]

Debugging

Debugging is the process of finding and fixing “bugs”(errors) in your program.

Bugs can be of different forms, Some bugs that you would find in the following questions include instructions that have been typed in wrong, wrong logic, punctuation errors, missing instructions, wrong data, etc.

(1)   Here is a program for tracing the number 2 as seen on a digital clock using Pro-Bot. Each side of the figure is 6 cm long. Try programming your Pro-Bot with this program and see if it makes the required pattern. If it does not, find the bugs in your program (the parts of the program that are not working correctly) and fix them. Circle the wrong instructions in the given program and write the correct ones instead.

Fd 6

Rt

Fd 6

Rt

Fd 6

Rt

Fd 6

Lt

Fd 12

(2)   Here is a program for tracing the following figure using Pro-Bot. Each side of the figure is 6 cm long. Try programming your Pro-Bot with this program and see if it makes the required pattern. If it does not, find the bugs in your program and fix them. Circle the wrong instructions in the given program and write the correct ones instead.

Rpt 2 [

Fd 6

Lt

Rpt 3 [

Fd 6

Rt

]

Rt

Rt

(3)   Here is a program for tracing the following figure using Pro-Bot. Each side of the figure is 6 cm long. Try programming your Pro-Bot with this program and see if it makes the required pattern. If it does not, find the bugs in your program and fix them. See if you need to add any other instructions as well. Circle the wrong instructions in the given program and write the correct ones instead.

Rpt 2 [

Rpt 5 [

Fd 6

Rt

]


(4)  Here is a program for tracing the figure below using Pro-Bot. Each side of the square is 6 cm long. The square is divided into two equal parts by the line in the middle. Try programming your Pro-Bot with this program and see if it makes the required pattern. If it does not, find the bugs in your program (the parts of the program that are not working correctly) and fix them. Circle the wrong instructions in the given program and write the correct ones instead.

Rpt 4 [

Fd 6

Rt

]
Fd 2
Rt
Bk 6

(5) Here is a program for tracing the following figure using Pro-Bot. There are three squares stacked up and each square has 6 cm long sides. Try programming your Pro-Bot with this program and see if it makes the required pattern. If it does not, find the bugs in your program and fix them. See if you need to add any other instructions as well. Circle the wrong instructions in the given program and write the correct ones instead.

Rpt 2 [
Rpt 5 [

Fd 6

Rt

]
]

Click here to see the debugged versions of the above programs.