The word "10021" is a numerical term used to represent a specific quantity. Its correct spelling follows the International Phonetic Alphabet (IPA) guidelines. The IPA transcription for "10021" is /ˈwʌn.tʊ.tuː ˈtuː.wʌn/. The first syllable, /ˈwʌn/, represents the number 1, while the second syllable, /tʊ/, represents the number 0. The third syllable, /tuː/, represents the number 0 again. The fourth syllable, /tuː/, represents the number 2 and the final syllable, /wʌn/, represents the number 1. Proper spelling of "10021" is essential for accurate communication in writing and speech.