This sound is /w/, as in the word 'when.' This letter combination used to make a /hw/ sound, a kind of unvoiced version of /w/, but that sound is obsolescent in American English. Linguists call this the “wine-whine merger.” There are some areas of the southeastern United States where people still observe that distinction, but even there it’s not the predominant pronunciation. It would be a useful distinction because many words become homophones without it, like ‘wear’ and ‘where.’ But there’s no use in fighting this change in our language. So, just teach this letter combination as sounding the same as when there is no ‘h’: /w/. The International Phonetic Alphabet (IPA) represents this phoneme with the following symbol: w. By this point in Once’s curriculum, the instructional content renders this letter combination as ‘wh’ in Times New Roman font. In these middle stages of the curriculum, the instructional content will have phased out the specialized orthography that helped beginning readers (pre-kindergarten students through early elementary grades) learn letter-sound correspondence more quickly.