Preference shares

If an exam question says 8% redeemable preference shares were issued on 1 April 20×8 @ par for $20 million, and the dividend paid was $800,000 within the year.
The question requires the preparation of a single entity financial statements from a trial balance as at 30 Sep 20×8

Question
To calculate a full year dividend?
Is it 8% of $20million = $1600,000

The period of time that the preference shares were issued is 6 months.

$1600000×6/12 = $800,000 dividend paid on trial balance.

Accural the remaining 6 mths =$800 000. Should the accural be $400, 000? The answer in the exam kit (CANDEL Q.351) says to accrual $400.
I am not sure how the $400 was worked out.