Here's why:
* The vowel sound in "scheme" is similar to the vowel sound in "stem" or "gem." These are all short vowel sounds.
* Long vowel sounds typically have a vowel followed by a silent "e" at the end of the word, or a vowel followed by a consonant and then a silent "e." For example, "fame," "bike," or "hope." This is not the case with "scheme."
Let me know if you have any other words you'd like to check the vowel sounds of!