The square of 12 is 144, also known as a gross. 12 is a dozen. 13 is a baker's dozen, and twice 13 is 26. Interestingly, though it is rare for one to achieve this, for every $100 a person successfully invests at an average annual performance rate of 26% there will be $1000 at the end of 10 years (assuming in a tax deferred account and with all distributions reinvested at the same rate of return). So, in saving and investing, it can be fun to play with numbers, and they often are our friends.
Take again, for instance, a gross, or 144. Ben Graham became famous for teaching and practicing the art of value investing, indicating that his firm had managed average gains of 20% a year using the methods he had suggested. He also in his later writings had advocated that among the general investing public it might make sense to sell value assets within a couple years. It turns out that an investment held two years which provides an annualized total return of 20% is at the end of that period worth 144% of the cost basis. Since Graham also suggested that the average value investor seek gains of 50% or better and sell after about two years, yet for more sophisticated investors he thought a longer holding period might be appropriate, one of my own formulas for stocks with good value and margin of safety has been: Buy with low debt to equity and at a 33% or greater discount to book value, and then hold till up at least 50% or till the market value represents the greater of 144% of the cost basis (if kept for two years) or till it can be sold at a 20% net annual total return (if kept longer).*