# How can I calculate (0.999...) on a calculator?

#### Pegleggedninja

Does anyone know how to do this? I've searched and searched online.

#### topsquark

Math Team
You are just trying to get 0.999999999999999999999999999999999999999999999 on your calculator? Why not just type it in? You could also do 1/1.00000000000000001. On some calculators you can potentially tell it to compute 1/3 as a decimal, then multiply the decimal by 3.

-Dan

#### SDK

.999... = 1 so just type 1?

topsquark

#### skeeter

Math Team
$$\displaystyle 0.999... = \sum_{k=1}^\infty \dfrac{9}{10^k} = \dfrac{9}{10} + \dfrac{9}{100}+ \dfrac{9}{1000} + \, ...$$

and on my calculator ...

... well, looks like SDK was correct.

topsquark