To decode words, we have to break them into syllables.
To do this, we look for patterns.
If there is one consonant between two vowels, first try dividing the word after the first vowel; if that doesn’t work, try dividing after the consonant.
For now, we will work with dividing the word after the first vowel.

If we divide after the first vowel and an open syllable is created, the vowel will typically make its long, open sound. 

Of course it can also become a schwa in speech, especially if it is unaccented.