7 - some examples from Revelation

1. Seven churches in Asia (Revelation 1-3)
2. Seven spirits that are before Christ's throne also described as seven lamps (Revelation 1:11, 3:1, 4:5)
3. Seven golden lampstands, representing the churches and among which Jesus walks (Revelation 1:12, etc)
4. Seven stars held in Christ's right hand, representing the angels of the churches (Revelation 1:16, 20)
5. Seven seals on the scroll opened by the Lamb (Revelation 5:1, 5)
6. Seven horns and eyes, the number the Lamb has and that are the seven spirits (Reveltaion 5:6)
7. Seve trumpets blown by seven angeels (Revelation 8:2, 6)
8. Seven thunders that spoke and whose words were not recorded (Revelation 10:3, 4)
9. Seven heads with seven crowns are the number on the great red dragon and seven heads with no crowns the number on the beast (Revelation 12:3, 13:1)
10. Seven plagues in seven bowls full of God's wrath poured out on earth by seven angels (Revelation 15:1, 6-8, 16:1, 17:1)

(Seven heads are also found on the beast the woman rides. These are seven hills and seven kings, five already fallen (Revelation 17:3, 7-11))