Yes, we looked at that, but closeTo: uses a much larger epsilon than Float's class variable Epsilon.
Yeah, that implementation is a bit strange ;-)
As far as I understand the method uses an epsilon value relative to the bigger absolute value of the two numbers. Depending on the exact behavior you want, you might need to write your own extension method indeed.
Number>>closeTo: aNumber epsilon: anEpsilon ^ self between: aNumber - anEpsilon and: aNumber + anEpsilon
Lukas