this is a simple model made of 3 shets of paper - i used to have much fun evolving it in my hands, just as the children do with the kaleidoscope..
Step 1: Step 1
Fold the square sheet in half and then along the dashed lines
Step 2: Step 2
fold again along the dashed line and unfold so that the line divides the sheet in halves
Step 3: Step 3
again fold and unfold along the lines
Step 4: Step 4
What you have now looks like this... now for the hard part
Step 5: Step 5
Fold along the line going from the left top corner to the right lower corner
Step 6: Step 6
Now repeat Step 5 for the other two corners
Step 7: Step 7
Fold along the lines forming a rhomb
Step 8: Step 8
What you have now must look like this...
Step 9: Step 9
Now just repeat steps 1 - 8 for the other two squares, now we have all the modules we need to form our toy...
Step 10: Step 10
Unfold the squares and lay one atop the other as shown in the picture
Step 11: Step 11
Now close the sides so that one square envelopes the half of the other...
Step 12: Step 12
Now for the tricky part - fold the whole thing as shown in the picture and stuf the free end of one module in the other as the black arrow shows.
Step 13: Step 13
You'll have something like this... Now push the module all the way in as the arrow shows
Step 14: Step 14
And you get the prism - like this one
Step 15: Step 15
Fold all the sides of your prism by the lines shown in the picture. It may seem tricky but all the needed lines are allready there, you only need to fold the sides of the prism along them.
Step 16: Step 16
Now our soon to be toy looks like this. Push the 3 corners shown by the arrows down, so they collapse to the middle of the model
Step 17: Step 17
Top elevation, just push the marked corners down gently
Step 18: Step 18
The result of steps 16 and 17 is shown here. Now again push the 3 corners to the middle of the model
Step 19: Step 19
Almost there by now ! Push the 3 outer corners to the middle for the third time and...