Summary: There was an uncovered edge case where number close to the whole was forced to round down because it was considered non-whole and had forced flooring. This diff covers that + adds a bunch of test cases to cover rounding function
Reviewed By: emilsjolander
Differential Revision: D5465632
fbshipit-source-id: 57e11092a97eba5dd76daad15fa8619535ff9c1b