Yeah, this is a nice trick. Also, 72 is a good number because it can easily be divided by a bunch of numbers (1, 2, 3, 4, 6, 8, 9). 5 and 10 aren't hard eithe

Yeah, this is a nice trick. Also, 72 is a good number because it can easily be divided by a bunch of numbers (1, 2, 3, 4, 6, 8, 9). 5 and 10 aren't hard either, and these interest rates are the ones you are most likely to see.