My father's age is $1222_{3}$, in base three to represent his three lower limbs -- two legs and a cane.  How old is he in base ten?
To convert a number from base three to base ten, I need to multiply each digit by the corresponding power of three and add up the results. For example, $1222_{3} = 1 \times 3^3 + 2 \times 3^2 + 2 \times 3^1 + 2 \times 3^0$. I get $1222_{3} = 1 \times 27 + 2 \times 9 + 2 \times 3 + 2 \times 1$. I get $1222_{3} = 27 + 18 + 6 + 2 = 53$. 