mˈɛltsɚ wʌz hˈaɪɚd baɪ ðə mˈʊɹ skˈuːl ʌv ˌɛndʒɪnˈɪɹɪŋ ˈæftɚ ɡɹˈædjuːˌeɪɾɪŋ tə pɚfˈɔːɹm wˈɛðɚ kˌælkjʊlˈeɪʃənz, mˈeɪnli bɪkˈʌz ʃiː nˈuː hˌaʊ tʊ ˈɑːpɚɹˌeɪt ɐn ˈædɪŋ məʃˈiːn; ɪn nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi θɹˈiː, ʃiː wʌz hˈaɪɚd tə pɚfˈɔːɹm kˌælkjʊlˈeɪʃənz fɔːɹ bɐlˈɪstɪks tɹədʒˈɛktɚɹiz.
Meltzer was hired by the Moore School of Engineering after graduating to perform weather calculations, mainly because she knew how to operate an adding machine; in 1943, she was hired to perform calculations for ballistics trajectories.