The Pi Necklace lists the first 100 decimal places of everyone's favorite irrational number, pi. It's the perfect accessory for Pi Day, or any other day, for that matter. [RGB Laboratory via Craziest Gadgets]
Uh, that's not 100 decimal places...
3.142 has three decimal places.
Decimal places occur on the right side of the decimal point.
Significant figures include all the numbers.
3.142 has four significant figures.
That necklace has Pi figured to 99 decimal places.