OMG! Credit Card Antenna Geometry is so cool + some PIN Probability

The world  has mostly agreed on the size of a credit card:

Credit cards today contain a microchip and aerial.

A credit card is dissolved in ACETONE (solvent found in some nail polish removers) to extract the chip & aerial in this BBC video.

 

OMG! The cardless chip still works to pay for coffee. But if you wanted cash you would still need the PIN.

Sasha a little dog with a BIG, BIG ID Number!

This exercise works best if for homework the middle school students count the digits in their own cell phone, passport, bill code or some other number. They don’t have to show the passport or bill. They just have to count the digits.