Following are a number of back-translations of Acts 2:41:

• Uma: «Many were the people that believed Petrus’s words, and they were baptized as/becoming followers of Yesus. On that day, the amount of people who believed in Yesus, was-added-to by about three thousand.» (Source: Uma Back Translation)
• Yakan: «Many believed what Petros said and they were bathed/baptized as a sign that they now trusted in Isa. That day more or less three thousand people were added to the ones trusting in Isa.» (Source: Yakan Back Translation)
• Western Bukidnon Manobo: «And then many believed that which Peter caused them to understand, and they had themselves baptized. And on that day the believers were increased by three thousand.» (Source: Western Bukidnon Manobo Back Translation)
• Kankanaey: «And many believed/obeyed what he was saying and they got-baptized. The number of those who-were-added to them who believed on that day, it was about three thousand.» (Source: Kankanaey Back Translation)
• Tagbanwa: «Well, without anything further, those who believed/obeyed that which he had said had themselves baptized. That day, three thousand was the number of those who were added to the believers in Cristo.» (Source: Tagbanwa Back Translation)

Chichimeca-Jonaz. «So like that, they who believed his saying they went and were baptized and that one-and-the-same day many, like 3000 people, entered and joined with them.» (Source: Viola Waterhouse in Notes on Translation August 1966, p. 86ff.)