Carrying Value with residual value

Hello Sir, In the following question of Bpp kit For the calculation of the carrying value they deducted the residual value from the cost and then they minus the depreciation is that correct, Thanks, Isaac & Joseph Co purchased new machinery on 1 January 20X5 for $1,000,000. It has a residual value of $200,000, with the useful life deemed to be 8 years. The plant is depreciated on a straight-line basis. Tax allowances of 50% of the cost of the asset can be claimed in the year of purchase, as depreciation is not allowed for tax purposes. The rate of income tax is 30% Identify whether a deferred tax asset or liability should be recognised at 31 December 20X5 and at what amount? Asset or Liability Amount ($) Asset 90,000 Liability 82,500 60,000 Answer Asset / liability Amount ($) Liability 60,000 As the tax base is less than the accounting carrying amount (more tax benefit has been taken), then deferred tax liability is required: Carrying amount $'000 Cost of asset 1,000 Residual value (200) Depreciable value 800 Depreciation charge 800/8 years (100) Carrying amount at 31 December 20X5 700 Tax base Cost of asset 1,000 Less Y1 tax allowance at 50% (500) 500 Difference $700,000-$500,000 200 Tax liability 30% x $200,000 60