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To use offline, download and unzip 4balls2boxes_v3.zip.

Then, double-click on 4balls2boxes.html. How do I do all this?

Scratch file designed by Linda Fahlberg-Stojanovska.

Activity Notes

We have 4 balls - 2 Reds and 2 Greens. We drop them randomly into 2 boxes.
Are the colors mixed or separate?

These two events are mutually exclusive and complete.

(a) Both boxes will have will have 1R & 1G.
   We call this event: MIXED colors.

(b) One box 2G, other box 2R.
   We call this event: SEPARATE colors.

Guided Activity

Do the experiment 200-1000 times.

  • What is the percent of mixed?
  • What is the percent of separate?

Now for some dreaded theory ...
Number the balls:

  • How many different ways can the balls drop into the boxes?
  • How many times does mixed occur?
  • Does your theory match your experiment?

"Mutually exclusive" meaning both events cannot happen at same time and "complete" meaning no other event can occur.

  • To change Scratch file, download and install freeware Scratch. See Scratch-MIT for more information.

Related Topics



LFS  —  27 September 2008, 15:12  



Dani  —  10 September 2008, 08:47  

This is really very useful program.


I will share it with others.




 Up one level

Page last modified on September 27, 2008, at 03:12 PM