Almost the same as oooo, but shorter and looser. Lips a little round, but relaxed, and your tongue drops a little — the oo in 'book' and 'good'.
Check yourself: Say 'food', then 'good'. Feel your lips RELAX on the second one, and notice it is shorter.
Watch for: /uː/. Arabic has long and short u, but they are the same vowel held for different lengths — this one is a different vowel, not a shorter one, and that is the thing to teach.
◆ marks a word that does NOT follow today's pattern — Blumenfeld boxes these on the page. Teach it by heart; do not let the class sound it out and lose faith in the rule.
Say the word, have them repeat it, count the sounds on fingers, THEN write. The count is what stops a child writing the first letter and guessing the rest.