Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_5 (casualties INTEGER, number VARCHAR)
### Question:
What is the average number of casualties for the convoy with a number of U-844?
### Answer:
SELECT AVG(casualties) FROM table_name_5 WHERE number = "u-844"