Example prodigal in lesson 9 ( revision kit)

This is other question which asked before but my problem is similar to her so I hope tutor can help us
Hi everyone, I’m confused about this question.

(Prodigal) (Sentinel)
Revenue 450,000 240,000
Cost of sales (260,000) (110,000)
On 1 October 20X0 Prodigal purchased 75% of the equity shares in Sentinel. The acquisition was through a share exchange of two shares in Prodigal for every three shares in Sentinel. The stock market price of Prodigal’s shares at 1 October 20X0 was $4 per share

The following information is relevant:
Immediately after the acquisition of Sentinel on 1 October 20X0, Prodigal transferred an item of plant with a carrying amount of $4 million to Sentinel at an agreed value of $5 million. At this date the plant had a remaining life of two and half years. Prodigal had included the profit on this transfer as a reduction in its depreciation costs. All depreciation is charged to cost of sales.

Answer:
1.10.20X0 Profit on transfer (5,000 – 4,000) 1,000
Proportion depreciated (½ / 2½) = (200)
Adjustment to plant 800
Required adjustment:
Dr Cost of sales (and retained earnings) 850
Cr Plant 800
Cr NCI (200 × 25%) 50
Note that the excess depreciation is credited to the subsidiary. This is netted
off against the unrealised profit in group cost of sales, but 25% must be
credited to the NCI

===> Cost of sales in CONSOLIDATED STATEMENT OF PROFIT OR LOSS : (260,000 + (110,000 × 6/12) + (W3) 800
NCI: Non-current asset PURP (W3) excess depreciation 200

My problem is why they adjust to plant 800 for cost of sales and 200 for NCI.
Thank you verymuch