Simplify:
$$256+25.6+2.56+0.256+0.0256=?$$

Align the decimal points vertically and add the numbers:
\begin{array}{r@{\quad}l} 256.0000 \\ +\ \ 25.6000 \\ +\ \ \ \ 2.5600 \\ +\ \ \ \ 0.2556 \\ +\ \ \ \ 0.0256 \\ \hline 284.4416 \end{array}

Let's double-check by standard addition from right to left:

* 4th decimal place: $6$
* 3rd decimal place: $6+5=11$ (write $1$, carry $1$)
* 2nd decimal place: $6+5+2+1\text{ (carry)}=14$ (write $4$, carry $1$)
* 1st decimal place: $6+5+2+0+1\text{ (carry)}=14$ (write $4$, carry $1$)
* Units place: $6+5+2+0+0+1\text{ (carry)}=14$ (write $4$, carry $1$)
* Tens place: $5+2+1\text{ (carry)}=8$
* Hundreds place: $2$

Result $=284.4416$