If a number increased by 10% becomes 88, then the number is

The number is increased by $10\%$

$10\%$  of 100$=10$

$\therefore$ Increased number $=110$

$\downarrow \begin{array}{cc}\text{Original number}& \text{Increased number}\\ 100& 110\\ x& 88\end{array}\downarrow$

$\frac{x}{100}=\frac{88}{110}$

$x=\frac{88}{110}\times 100$

$\boxed{x=80}$

$\therefore$  New number is 80.