Abstract: A base with a referenced concave surface and a movable indicator form a putting aid which indicates direction and amount of slope on a golf green. Diametrically opposed sighting rods provide convenient and accurate visual alignment while the putting aid is situated down upon the golf green. Arrowheaded linear, transverse linear and concentric circular indicia located upon the concave surface serve as reference markings. A first method of operation includes facilitating the training of a golfer to putt a golf ball into a golf hole by aligning the putting aid between the golf ball and the golf hole such that the sighting rods and arrow indicium are aligned with an imaginary direct line between the golf club and the golf hole.