Mark Zuckerberg and Priscilla Chan to give away 99% of their shares of Facebook

That sounds like an awful lot of their Facebook shares.  They want to help create a better world for their daughter, Max. I wonder if they will have enough left over to live on? The BBC newspaper said that their gift amounted to $45 billion dollars at Facebook's present value! So .... how much will they have left? Without pre-teaching how to solve for this, allow students to come up with their own ideas and strategies.  Focus on different ways that students determine the amount of money they will have remaining.  Students might have many different ways of thinking about the problem including the use of ratio tables, diagrams or algebra. 

A whole additional and important conversation to be had: how could they use that money to make the world a better place?