By comparing the form of several yupanas, researchers found that calculations were based using the Fibonacci sequence 1, 1, 2, 3, 5 and powers of 10, 20, and 40 as place values for the different fields in the instrument.
baɪ kəmpˈɛɹɪŋ ðə fˈɔːɹm ʌv sˈɛvɹəl juːpˈɑːnəz, ɹᵻsˈɜːtʃɚz fˈaʊnd ðæt kˌælkjʊlˈeɪʃənz wɜː bˈeɪst jˈuːzɪŋ ðə fˌɪbənˈɑːtʃi sˈiːkwəns wˈʌn, wˈʌn, tˈuː, θɹˈiː, fˈaɪv ænd pˈaʊɚz ʌv tˈɛn, twˈɛnti, ænd fˈoːɹɾi æz plˈeɪs vˈæljuːz fɚðə dˈɪfɹənt fˈiːldz ɪnðɪ ˈɪnstɹəmənt.