  In this paper we study sums and products in a field. Let $F$ be a field with
${\rm ch}(F)\not=2$, where ${\rm ch}(F)$ is the characteristic of $F$. For any
integer $k\ge4$, we show that each $x\in F$ can be written as $a_1+\ldots+a_k$
with $a_1,\ldots,a_k\in F$ and $a_1\ldots a_k=1$ if ${\rm ch}(F)\not=3$, and
that for any $\alpha\in F\setminus\{0\}$ we can write each $x\in F$ as
$a_1\ldots a_k$ with $a_1,\ldots,a_k\in F$ and $a_1+\ldots+a_k=\alpha$. We also
prove that for any $x\in F$ and $k\in\{2,3,\ldots\}$ there are
$a_1,\ldots,a_{2k}\in F$ such that $a_1+\ldots+a_{2k}=x=a_1\ldots a_{2k}$.
