Adding one more references:
Dgraph records this like this
<_:uid2711> <test> "3.779697544E+01"^^<xs:float> .
Also supporting BigDecimal types could be related to this.
https://github.com/dgraph-io/dgraph/issues/926
Also can be related Inferred schemas treat integers as floats, may silently alter data · Issue #2377 · dgraph-io/dgraph · GitHub