Horseman advancing right, holding a spear, no mintmark / Inscription in five lines "KNZ bVELIKIY VSEYA RUSY" ("Grand Duke of all Russia"). 13mmx12mm, 0.65 grams. Novgorod mint. Griszin #75; Russian Wire Coins #75.
This is a full kopeck (not a denga), weighing over 0.6 grams. The coin was minted in Novgorod around 1540 when Ivan was still just a Grand Duke and not a Tsar.
The infamous Ivan "the Terrible" was the Grand Duke of Russia between 1533 and 1547. In 1547 he assumed the supreme title of "Tsar" ("Caesar") and ruled as such until his death in 1547.