the 1 in 1.06 gives you the 479.25 and the .06 in i.06 gives you the six percent so you can do the computation in one operation with a calculator, if you know algebra!
There are many helpful tricks to use in math. I use some of them myself. For instance if someone asks you to multiply 19 X 44 - I just add a zero to the 44 (440), double it (880)then subtract one of the 44s (since there are 19 and not 20 of them). Answer is 836. I can do it in my head much faster than a calculator. Math is full of short cuts like this.
If you know Algebra, you can calculate at what temperature a Celsius or Fahrenheit thermometer reads the same (as you are reaching for an extra sweater).