Quantity, ten pieces.

Length of time, 30 minutes.

Time: 5 pm

ころ /ごろcan only indicates the left and right sides of the time point.

5 p.m.

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His verb て +ぁるindicates is a continuation of the state after the action.

The state left after writing.

The book ぃたぁります is a grammatical error. The two books ぁた and ぁる are verbs and cannot be directly connected.