ˈæbækəsbˈeɪst mˈɛntəl kˌælkjʊlˈeɪʃən ˌeɪˌɛmsˈiː, wˌɪtʃ wʌz dᵻɹˈaɪvd fɹʌmðɪ ˈæbækəs, ɪz ðɪ ˈækt ʌv pɚfˈɔːɹmɪŋ kˌælkjʊlˈeɪʃənz, ɪŋklˈuːdɪŋ ɐdˈɪʃən, sʌbtɹˈækʃən, mˌʌltɪplɪkˈeɪʃən, ænd dᵻvˈɪʒən, ɪnðə mˈaɪnd baɪ mənˈɪpjʊlˌeɪɾɪŋ ɐn ɪmˈædʒɪnd ˈæbækəs.
Abacus-based mental calculation (AMC), which was derived from the abacus, is the act of performing calculations, including addition, subtraction, multiplication, and division, in the mind by manipulating an imagined abacus.