what is one third as a decimal

Here do it this way, and cover all the bases!

$$\frac{1}{3}=0.33\overline 3(\dot 3)...$$

$${\frac{{\mathtt{1}}}{{\mathtt{3}}}} = {\mathtt{0.333\: \!333\: \!333\: \!333\: \!333\: \!3}}$$

The 3's go on forever.

$${\frac{{\mathtt{1}}}{{\mathtt{3}}}} = {\mathtt{0.333\: \!33}}$$

Actually, the decimal wil just keep going to forever with 3's.

Thus, you could write the decimal as .333 with  a line over the 3's, meaning it well just keep going on and on and on.

$$\frac{1}{3}=0.\dot3$$

This is read as 0.3 repeater OR  0.3 recurring.

The dot means that the 3 repeats for ever!

(Ninja, you said a line, I've never seen that before, I've only ever seen a dot used.)

Oh really? I've always seen it as a line over the top.

It might be different in different places around the globe too.

Straight from the Wikipedia's mouth.....

"While there are several notational conventions for representing repeating decimals, none of them are accepted universally. In the United States, the convention is generally to indicate a repeating decimal by drawing a horizontal line (a vinculum) above the repeated numerals (). In mainland China, the convention is to place dots above the outermost numerals of the repeating digits (). Another notation sometimes employed in Europe is to enclose the repeating digits in parentheses (). Repeating decimals may also be represented by three periods (an ellipsis, e.g., 0.333…), although this method introduces uncertainty as to which digits should be repeated or even whether repetition is occurring at all, since such ellipses are also employed for irrational decimals such as 3.14159…"

Hey....they said it....I didn't !!!!

Thanks Chris.

I have always done it 'China's' method (and I am Australian)

A dot above the first to repeat and a dot above the last to repeat.

Good one , Anon.    !!!!

It actually goes on forever but at he very very end there is a 4.