round_significant

# File activesupport/lib/active_support/number_helper/rounding_helper.rb, line 35
        def round_significant(number)
          return 0 if number.zero?
          digits = digit_count(number)
          multiplier = 10**(digits - precision)
          (number / BigDecimal(multiplier.to_f.to_s)).round * multiplier
        end