Vtg 1979 Mattel Thoroughbred Horse Race Analyzer w/ Unused Pad & Case Powers On

Vtg 1979 Mattel Thoroughbred Horse Race Analyzer w/ Unused Pad & Case Powers On Unit is tested and I will say this; it powers on, and the numeric buttons display, but I don't know how to operate it, so I cannot say for sure if it functions as it should. Minor battery corrosion has been cleaned and does not impact function. Includes full pad of unused race scorecards, and original case, which has significant wear and mildew staining. Operates using a 9v battery, which is not included.