i believe the original poster, JenniferG, was just after doing a sanity check on her two meters (one 5½ digits benchtop, the other 4½ digits handheld). i'm picking that the Instek GDM-8251A (benchtop) is far more likely to be reading true.
for this sort of check one doesn't need anything too fancy, and a 0.01% resistor of known value and a 5v MAX6350 or similar would be fine. no need to go overboard buying a "DMMCheck Plus" or similar. indeed, for the average electronics hobbyist, a 2% accuracy 3½ digit multimeter is mostly fine!
cheers,
rob :-)