'Myriads' in the Bible

and many of those who had practised the curious arts, having brought the books together, were burning them before all; and they reckoned together the prices of them, and found it five myriads of silverlings;

and they having heard, were glorifying the Lord. They said also to him, 'Thou seest, brother, how many myriads there are of Jews who have believed, and all are zealous of the law,