Warm up

Look at these playing cards:

http://polypad.org/qewkMjEOFIdpvA

1. Do you notice any particular pattern about the cards?
2. What is the total of

• first two cards?
• first three cards?
• first four cards?

1. Have you noticed something special? Is there a link with the next card?

Main activity

Look at these groups of four playing cards:

http://polypad.org/MbPv4RpgKsA2HA

1. Count the number of shapes in all these groups of four cards.
2. What number of shapes can we get with such cards?
3. Could you create a shortcut to write the numbers we can get like a code? Complete the following table:

http://polypad.org/EquFmsdwokYEJA

1. What is the biggest number we can get with four cards?
2. with five cards?

Binary demo - Polypad - Mathigon

You’ve just learned how to write integers in base 2 (by adding the powers of 2)!