Math CentralQuandaries & Queries


Question from Loretto, a parent:

If i save a penny and it doubles every day for one year how much will i have saved in that year

(1) Look for a pattern: 2c (after one day), 4c (after 2 days)...

(2) Write this as a formula: 2 to the power n after n days.

(3) Try to compute this: 2365 Your calculator may return an error because the number is too big. Otherwise you get about 7.5 x 10109 c or $7.5x10107, a number far too big to be meaningful as money.

Let's explore this. Divide by $1000 to convert approximately to ounces of gold.

7.5x10104 oz

or more than 10103 kilograms of gold.

Now look up the mass of the observable universe on the Internet.

Good Hunting!

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