I have a file with 40,000 rows 

```
head flower_all

    0.992957746478873 0.00704225352112677
    0.646410833917366 0.353589166082634
    0.992957746478873 0.00704225352112677
    0.992957746478873 0.00704225352112677
    0.992957746478873 0.00704225352112677
    0.992957746478873 0.00704225352112677
    0.992957746478873 0.00704225352112677
    0.992957746478873 0.00704225352112677
    0.5 0.5

```

I want to keep only 3 significant digits.
My desired output:

```
0.992 0.007
0.646 0.353
0.992 0.007
0.992 0.007
0.992 0.007
0.992 0.007
0.992 0.007
0.992 0.007
0.5 0.5

```

How can I do it?