lib/active_record_survey/node/answer/scale.rb
def validate_instance_node(instance_node)
			# super - all validations on this node pass
			super &&
			(instance_node.value.to_s.empty? || !instance_node.value.to_s.match(/^(\d+(\.\d+)?)$/).nil?)
		end
def validate_instance_node(instance_node)
			# super - all validations on this node pass
			super &&
			(instance_node.value.to_s.empty? || !instance_node.value.to_s.match(/^(\d+(\.\d+)?)$/).nil?)
		end
Accept integer, float, or empty values