Question

How do you write 1 and 1/3 as a decimal?

Answer 1

`1 1/3 = 1.33dot3`

Explanation:

Note the "dot" over the final `3` in the Answer above which is used to indicate that the `3` reoccurs infinitely.
`1.dot3` and `1.3dot3` and `1.33dot3` and so on, all represent the same value.

If more than a single digit is to be repeated a "dot" should be placed over both the first and last digit of the repeated sequence,
So, for example:
`2.35dot8 21dot7 = 2.358217dot8 21dot7 = 2.3582178217dot8 21dot7` and so on.

At least that was how I was taught to do it.

Answer 2

1.3 with a little line over the 3.

Explanation:

The line (called a vinculum) can't be typed here, but it signifies that the 3 repeats. The number without that is 1.3333333333333333333333... and so on.