SQLite Left join tables after two queries

I'm trying to perform a join between two tables as written below. I'm at a loss at what to look for and what to troubleshoot. Any ideas on what I'm missing?

SELECT * FROM
(SELECT PART_NUMBER, PART_DESCRIPTION, AVG(JOB_QUANTITY_SCHEDULED) FROM JOBS GROUP BY PART_NUMBER)
    left join
(SELECT ITEM, ITEM_COST,  COSTING_LOT_SIZE, FIXED_DAYS_SUPPLY FROM ITEM_ATTRIBUTE)
    ON JOBS.PART_NUMBER == ITEM_ATTRIBUTE.ITEM

Am getting the error

no such column: JOBS.PART_NUMBER: