Determines if another number is approximately equal within a given _n_th degree. Defaults to 100ths if the degree is not specified.

Rounds to the given decimal position.

  require 'facet/float/round'

  4.555.round_at(0)  #=> 5.0
  4.555.round_at(1)  #=> 4.6
  4.555.round_at(2)  #=> 4.56
  4.555.round_at(3)  #=> 4.555

Rounds to the nearest _n_th degree.

  require 'facet/float/round_to'

  4.555.round_to(1)     #=> 5.0
  4.555.round_to(0.1)   #=> 4.6
  4.555.round_to(0.01)  #=> 4.56
  4.555.round_to(0)     #=> 4.555