Mental Models: FI Math A few weeks ago, I talked about the importance of mental models to leveling up our problem-solving abilities. I came across an article in the Washington Post yesterday that happened to be about the UK coronavirus variant and its increased reproduction rate and I thought it was a perfect example for the FI Weekly. My bringing this up here isn’t necessarily about coronavirus, but the increased level of understanding we all have when we understand exponential math, the math behind the compound growth of our money, and mental models generally. The article noted that in a Facebook post, the Danish “Prime Minister Mette Frederiksen told people to imagine sitting in the top row of Copenhagen’s Parken Stadium, a soccer arena with a capacity of 38,000 people. A dripping tap is filling it up, one drop the first minute, two drops the second, four drops the third. At that rate, Frederiksen said, the park will be filled in 44 minutes. But it will seem almost empty for the first 42 minutes, she said. “The point is, you only realize that the water has risen when it’s almost too late.”” When you work backwards with it doubling every minute, the