Depreciation (Prodigal)

sir, again I present you the whole question but it is enough for us to look at the 2rd note here

On 1 October 20X0 Prodigal purchased 75% of the equity shares in Sentinel. The summarised
statements of profit or loss and other comprehensive income for the two entitiesfor the year
ended 31 March 20X1 are:
Prodigal Sentinel
$000 $000
Revenue 450,000 240,000
Cost of sales (260,000) (110,000)
––––––– –––––––
Gross profit 190,000 130,000
Distribution costs (23,600) (12,000)
Administrative expenses (27,000) (23,000)
Finance costs (1,500) (1,200)
––––––– –––––––
Profit before tax 137,900 93,800
Income tax expense (48,000) (27,800)
––––––– –––––––
Profit for the year 89,900 66,000
Other comprehensive income
Gain on revaluation of land (note (1)) 2,500 1,000
––––––– –––––––
Total comprehensive income 92,400 67,000
––––––– –––––––
The following extracts for the equity of the entities at 1 April 20X0 (before acquisition) is
available:
$000 $000
Revaluation surplus (land) 8,400 nil
Retained earnings 90,000 125,000
The following information is relevant:
(1) Prodigal’s policy is to revalue the group’s land to market value at the end of each
accounting period. Prior to its acquisition by Prodigal, Sentinel’s land had been valued
at historical cost. During the post?acquisition period Sentinel’s land had increased in
value over its value at the date of acquisition by $1 million. Sentinel hasrecognised the
revaluation within its own financial statements.

(2) 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.

(3) After the acquisition Sentinel sold goods to Prodigal for $40 million. These goods had
cost Sentinel $30 million. $12 million of the goods sold remained in Prodigal’s closing
inventory.
(4) Prodigal’s policy is to value the non?controlling interest of Sentinel at the date of
acquisition at its fair value which the directors determined to be $100 million.
(5) The goodwill of Sentinel has not suffered any impairment.
(6) All items in the above statements of comprehensive income are deemed to accrue
evenly over the year unless otherwise indicated.

MY QUESTION: in there i don’t understand why depreciation amount which is (5000-4000)/2.5*6/12= 200 added to calculation of NCI and deducted from COGS. what is the logical behind it. Because of that we always add depreciation amount to cogs and deducted from NCI, the book did vice versa. please clarify for me ?