Unwinding discount (Runner Co)

Sir based on this information which is from kaplan exam kit

On 1 April 20X4, Runner Co acquired 80% of Jogger Co’s equity shares when the retained
earnings of Jogger Co were $19.5m. The consideration consisted of cash of $42.5m paid on
1 April 20X4 and a further cash payment of $21m, deferred until 1 April 20X5. No accounting
entries have been made in respect of the deferred cash payment. Runner Co has a cost of
capital of 8%. The appropriate discount rate is 0.926.(at the year end is 31 March
20X5)

I calculate deferred consideration and unwinding discount like this:
Deferred consideration: 21,000 × 0.926= 19,446
Unwinding: 19,446 x 8% = 1552
total current deferred liability: 21,002

but in the book, the amount of unwinding is 1556 and find like this way: 21,000 – 19,446

My solution way always give me correct answer and i don’t catch why in here the answer is different