1 | initial version |

Convert your numbers to explicit rationals and ask whether their square root is in **Q**:

```
sage: sqrt(1671/1000) in QQ
False
sage: sqrt(256/100) in QQ
True
sage: sqrt(2) in QQ
False
```

Or you can do the conversions this way:

```
sage: sqrt(QQ(1.671)) in QQ
False
```

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