Task 16 ... Years 2 - 10


Attractive, apparently straightforward, foam shapes offer spatial challenges which can be quite devilish. Problem solving strategies such as try every possible case are called on (albeit informally) as spatial perception develops.


  • Panel of 8 foam shapes - some made from 7 squares and some from 6
  • Playing board, marker and cloth


  • sorting
  • spatial perception
  • shape recognition
  • perimeter & area
  • factors


A task is the tip of a learning iceberg. There is always more to a task than is recorded on the card.

Perimeter Puzzle 1

Perimeter Puzzle 2


  1. Place all the pieces on the table and mix them up. How many seconds does it take you to get them back into the frame. What is the class record?
  2. Select any two shapes and fit them together in any way. Draw the perimeter of this combined shape on centimetre grid paper. Repeat until you have at least 10 puzzles on the page. Challenge someone else to solve your perimeter puzzles.
    (Depending on student experience you might change this to 3 or 4 piece perimeter puzzles.)
    Two examples are shown opposite. They were made in minutes using a black square created in a drawing program. The square was copied and moved to create the perimeter puzzle. A great opportunity to combine mathematical work on shapes with learning how to control features of technology such as the drawing tools in Word.
  3. What is the longest possible perimeter of a 2 piece perimeter puzzle?
  4. Use centimetre grid paper to make more puzzles like the ones on the task card. If each student produces one puzzle you will have class set of challenging spatial puzzles.
  5. The eight pieces make a rectangle. How many squares are inside the rectangle?
  6. If there were other rectangles shapes which could be made from the 8 pieces, what are the only sizes they could be? (Squares are rectangles too.)
  7. Can any of these other sizes be made? How do you convince someone else?
  8. Can you make rectangles without using all the pieces? How many rectangles can be made? How do you know when you have found them all?

Whole Class Investigation

Tasks are an invitation for two students to work like a mathematician. Tasks can also be modified to become whole class investigations which model how a mathematician works.

You could turn this task into a whole class lesson by drawing an Octaflex set on the recording paper and copying it onto card. Hours later you would have cut out enough class sets - and they wouldn't look or feel anywhere near as good as the original. In truth, the only way to turn this task into a whole class investigation is to purchase more panels. Contact Ina Koetsier
inak@blackdouglas.com.au for a quote.

Is it in Maths With Attitude?

Maths With Attitude is a set of hands-on learning kits available from Years 3-10 which structure the use of tasks and whole class investigations into a week by week planner.

The Octaflex task is an integral part of:

  • MWA Space & Logic Years 5 & 6
  • MWA Space & Logic Years 9 & 10

Green Line
Follow this link to Task Centre Home page.