I will work from Young's literal translation, as all the [other] translations have an element of interpretation.

Dan 9:24 `Seventy weeks are determined for thy people, and for thy holy city, to shut up the transgression, and to seal up sins, and to cover iniquity, and to bring in righteousness age-during, and to seal up vision and prophet, and to anoint the holy of holies.

I don't think I need to prove that the 70 weeks represent 70x7 or 490 years. This completes God's plan of salvation. Christ himself is the fulfillment of prophecy & is the true tabernacle who was anointed at the start of his ministry. His finished work of redemption by the cross is God's declared plan by the end of 490 years.

Dan 9:25 And thou dost know, and dost consider wisely, from the going forth of the word to restore and to build Jerusalem till Messiah the Leader [is] seven weeks, and sixty and two weeks: the broad place hath been built again, and the rampart, even in the distress of the times.

I don't know why Gabriel separates seven weeks, and sixty and two weeks. Jerusalem & the temple were rebuilt for Christ to come 483 years after Artaxerxes' decree implemented by Ezra. [Ezra 7 - note 3 decrees are mentioned in Ezra 1:1ff, 6, & 7, & there is a forth in Nehemiah 2.]

Dan 9:26 And after the sixty and two weeks, cut off is Messiah, and the city and the holy place are not his, the Leader who hath come doth destroy the people; and its end [is] with a flood, and till the end [is] war, determined [are] desolations.

Note Gabriel says "after the sixty and two weeks" without specifying beginning, middle or end. We are now in the Roman (iron) kingdom. After Messiah is cut off, the city & temple will be destroyed, & war will continue until the end of time. There may be a translation problem here: most agree with the KJV: the people of the prince that shall come shall destroy the city and the sanctuary. That is a prophecy of AD 70. There is no need to place the destruction of the city within the 70 weeks.

Dan 9:27 And he hath strengthened a covenant with many -- one week, and [in] the midst of the week he causeth sacrifice and present to cease, and by the wing of abominations he is making desolate, even till the consummation, and that which is determined is poured on the desolate one.'

We are now into the events of week 70. "He" could be Messiah or "the leader" but as the run of the passage is referring to the work of Messiah, and here the covenant is referred to, I understand he to be Messiah. Christ was calling the people to himself during his ministry, & in the middle of the week he shed his blood of the New Covenant on the cross. Those Jews who responded to the Gospel continued stedfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers. The Covenant was being ratified during the 70th week. We can see that week ending with the stoning of Stephen. Up to that time the Gospel was preached even to the Sanhedrin leaders who opposed the Apostles.

Now the Jewish nation had no further purpose in God's plan of redemption. The saving work is finished. Christ has died & risen. Repentance is preached in his name to Jew & Gentile alike. Animal sacrifices no longer have a significance. The temple henceforth is to be built with living stones. Acceptable worship is no longer in this mountain nor at Jerusalem but in spirit & in truth. (Eph. 2, 1 Peter 2, John 4)

The abominable Roman eagles would surround Jerusalem & destroy it as further prophesied by the Lord Jesus in Matthew 24 & elsewhere.
I know that a popular interpretation divides the weeks, and postpones the 70th week for 1975 years & counting to after the rapture/resurrection. This is in no way justified by the text, and destroys the literal meaning of an amazingly literal prophecy. Scripture says 70 weeks, NOT 350 weeks.