Binary Unplugged: "Count the dots" for the smart board

This resource can be used on the classroom smart board to deliver the classic unplugged activity "Count the dots" to introduce binary numbers following a constructivist approach.

CLICK ON THE CARDS TO SHOW OR HIDE THE DOTS.

CLICK ON THE ARROW TO SHOW/HIDE THE DENARY EQUIVALENT.

CLICK ON THE SECOND ROW OF CARDS TO SHOW/HIDE THE BITS.

ASK FOR VOLUNTEERS TO STAND AT THE SMARTBOARD AND CLICK ON THE CARDS TO SHOW/HIDE THEM.

Instructions:

Extract the content of the zip file "binary-unplugged.zip" in a folder and click on "Count_the_dots.html" to start.

Read the instructions for the activity at http://csunplugged.org/binary-numbers/#Count_the_Dots

E.g. Ask all pupils at their desks and a student at the board:

1. what do you notice about the number of dots on the cards?

2. How many dots would the next card have if we added a 6th card on to the left?

3. And if we added yet another one?

4. How can we have exactly 5 dots showing?

5. And 29 dots?

6. We can use these cards to make numbers by turning some of them face down and adding up the dots that are showing. Ask the children to make 6 (4-dot and 2-dot cards), then 15 (8-, 4-, 2- and 1-dot cards), then 21 (16, 4 and 1)...

7. Now try counting from zero onwards. The rest of the class needs to look closely at how the cards change to see if they can see a pattern in how the cards flip (each card flips half as often as the one to its right).

8. When a binary number card is not showing, it is represented by a zero. When it is showing, it is represented by a one. This is the binary number system.

9. Ask the children to make 01001. What number is this in decimal? (CLICK ON THE ARROW TO REVEAL THE DECIMAL NUMBER)

10. What would 17 be in binary? (10001)

11. Try a few more until they understand the concept.

There are five optional follow-up extension activities, to be used for reinforcement. The children should do as many of them as they can.

etc. etc