How does a bigdecimal's precision change upon converting to string?

Question

I stumbled upon a very weird behaviour. A normal bigdecimal value when converted to string using to_s method changes it's behaviour.

There is a normal float column in my table and a record has the value 37502

When I fetch the record and print it in view using

"some text "+ my_record.amount.to_s

I get the output as

37502.0390625

I am perplexed with this behaviour