Turtle Challenge #209

Turtle Challenge 209 card

Challenge type: Turtle Challenges  ·  Difficulty: ★★★☆☆ Medium  ·  Language: Python

Grab a pencil. Sketch what you think this code will draw, then run it and compare.

Turtle challenge 209: the code is shown below as text too.
Read the code. What will it draw?
import turtle

t = turtle.Turtle()
t.speed(0)
t.pensize(2)
t.pencolor("tomato")

for petal in range(12):
    t.circle(40)
    t.left(30)

t.hideturtle()
turtle.done()

Think about it

  1. How many circles will the turtle draw?
  2. Why does the turtle turn 30 degrees after each circle?
  3. What colour is the flower?
Need a hint?

Read the loop first. How many times does it repeat, and what does the turtle do each time? Draw it on paper one step at a time, turning your pencil like the turtle turns.

Grown-ups: This code runs in IDLE, the editor that comes with Python. Open a new file, paste the code, save it (any name except turtle.py) and press F5. A window opens and the turtle draws.

For teachers and grown-ups

Skills practised: Reading code, tracing loops, and connecting angles and shapes.

The big idea: Reading code and predicting what it does (tracing) is as important as writing it.

Questions to ask:

  • How many times does the loop repeat?
  • How far does the turtle turn altogether?
  • Which single number would you change to make a different shape?

Take it further: Children sketch their prediction first, run the code in IDLE, then change one value and predict again.