Ask your kids if they can name any common words with the /oo/ sound. Read each word with them and help them pronounce it. Then, have them circle the words that have the /oo/ sound as in moon.
See if students understand syllables with this fun worksheet. It teaches them that a syllable is a word part with a vowel sound. Kids read each word and choose how many parts it has. Doing this often helps them decode new words and gain confidence.