Remembering the Women of the Mathematical Tables Project

Human computers, Jet Propulsion Laboratory.
Human computers, Jet Propulsion Laboratory. Public Domain | Wikimedia Commons

By Joy Lisi Rankin

In the years leading up to World War II, the largest computing organization in the United States was not at engineering powerhouse Massachusetts Institute of Technology, nor was it at then rapidly-growing International Business Machines (IBM). Rather, at its peak, The Mathematical Tables Project (MTP) located in New York City employed nearly 450 human computers under the auspices of the Works Project Administration (WPA). The MTP was a large-scale endeavor to produce the mathematical tables crucial to scientific work, and it modeled methods that are integral to contemporary digital computing.

We have overlooked the ways in which the project shattered expectations despite numerous obstacles — and how it owed that success largely to the diverse life experiences of two brilliant women, Dr. Gertrude Blanch and Ida Rhodes. Dissecting the quotidian operations of the MTP forces a reconsideration of how we define scientific success and what it means to be a successful scientist.

President Franklin Delano Roosevelt introduced the WPA during the Great Depression with the dual purpose of creating employment for millions of Americans suffering from the poverty of national economic collapse, and to develop public goods in the form of roads, bridges, schools, art, and more. Nearly a century later, it’s easy to forget that over 30 million adults had received less than an eighth-grade education during the 1930s, and the WPA provided the infrastructure of schools and teachers that later contributed to America’s postwar economic boom.

Yet, the WPA was controversial. Critics derided the massive public spending efforts as big government folly, and they mocked those employed by the WPA as “boondogglers.” These naysayers caricatured the boondogglers as lazy good-for-nothings, sucking the nation dry via their dependence on welfare relief. Such critics conveniently ignored the much larger structural problems that had contributed to national economic collapse, widespread unemployment, and unprecedented poverty. Defenders of the WPA pointed to the millions working and gaining experience not just for the WPA but also for future employment in the private sector as the economy recovered. A 1937 report in The Nation celebrated the WPA’s achievement in a mere 13 months of “29,000 miles of new roads, 1,099 school buildings, 1,440 recreational centers, and 3,350 miles of new trunk and lateral sewers…”

When the idea of a human computing organization was floated as a WPA project, scientists fell largely on the side of the naysayers. David Alan Grier, author of When Computers Were Human, reported one critic’s objections as emblematic of those of the scientific community: “Scientists, [the critic] argued, are successful people. The poor, he asserted, are not successful. Therefore, he concluded, the poor cannot be scientists and hence should not be employed in computation.” These 1930s scientists, like many people today, saw poverty as the result of some individual failing such as laziness, immorality, lack of intelligence, or lack of a “proper work ethic.” But then, as now, people who worked still lived in poverty.


When the idea of a human computing organization was floated as a WPA project, scientists fell largely on the side of the naysayers…These 1930s scientists, like many people today, saw poverty as the result of some individual failing such as laziness, immorality, lack of intelligence, or lack of a “proper work ethic.”


Dr. Gertrude Blanch and Ida Rhodes led the MTP to unexpected and unprecedented scientific and social success, proving these naysayer scientists wrong. Although the MTP originated as a WPA endeavor to employ out-of-work mathematicians, very few of the hundreds of MTP workers actually had mathematics education. Nevertheless, these MTP workers produced books of highly accurate and complex mathematical tables required for scientific, engineering, and military work. Crucial to their success was a novel division of labor in which lengthy calculations were broken down into very basic steps, along with tools such as worksheets that enabled workers to check their own work before it was passed to supervisors for review. Ultimately, the MTP employees were celebrated for their phenomenally comprehensive and accurate tables.

Blanch’s and Rhodes’s life experiences uniquely qualified them to transform hundreds of ordinary New Yorkers into an efficient, extremely reliable computing operation. Just as importantly, the were able to provide a sense of community, belonging, purpose – and skills and work history to carry to future employers – to their human computers.

Blanch demonstrated aptitude and passion for mathematics throughout childhood and was eager to pursue college. But when her father died in 1914, the same year she graduated high school, she sought employment to support herself and her mother. She spent the next 14 years in several clerical positions, ultimately rising to the role of office manager. At a time when Henry Ford’s assembly lines and Frederick Winslow Taylor’s studies of human efficiency were heralded and emulated, she likely learned about division of labor and efficient worker organization through her employment.

After her mother died, Blanch began taking night classes at New York University. Ultimately she graduated summa cum laude and was elected to Phi Beta Kappa — all while working full-time. When she told her employer Jacob Marks that she was quitting to attend college full-time, he sought to retain Blanch as his highly valued office manager, offering to pay her night school tuition if she continued working for his hat-making business.

After graduating NYU in 1932, Blanch completed her doctorate in mathematics at Cornell in 1935. Yet when she sought academic employment in the sciences, she carried the double stigma of being a woman and Jewish at a time when the academy was reluctant to hire either. Blanch ended up as second-in-command at the MTP, under the official head who was a Jewish man named Arnold Lowan. Blanch and Lowan stepped into these roles in part because the WPA effort was looked down upon by the scientific establishment, and even leadership roles were seen as lacking desirability or prestige.

Blanch relied on both of her realms of expertise in office management and mathematics to organize the MTP employees, many of whom had only basic arithmetic skills. Most were not even trained in working with positive and negative numbers. So Blanch faced the monumental task of organizing these workers and the work itself. Her mathematics expertise enabled her to break down complex equations into basic component parts.

Rather than talking about or training on positive or negative numbers, she implemented color coding with positive numbers in black and negative numbers were red. She hung up giant signs that her addition teams could see: black and black make black, red and red make red, black and red mean hand over to the subtraction team, and so on. Observing how her employees worked with addition enabled her to then put the more trained onto subtraction, multiplication, and so on. She devised worksheets that broke down problems into very basic component parts, and that enabled workers to check their peers for accuracy and consistency. These worksheets also allowed floor supervisors, and ultimately Blanch herself to review and double-check all that work. Blanch’s innovations transformed the work of computing and foreshadowed the way digital computers break down very complex problems into steps that can be performed one-by-one, with ones and zeroes.

Blanch’s right-hand woman, Ida Rhodes, was both a talented mathematician and nurse, which turned out to be crucial expertise for the employees who had polio, tuberculosis, epilepsy, and physical disabilities. Rhodes worked as a nurse to support herself, and like Blanch, she was a brilliant woman mathematician who earned a degree while working, who also happened to be Jewish.


Just as importantly, [Blanch and Rhodes] were able to provide a sense of community, belonging, purpose – and skills and work history to carry to future employers – to their human computers.


Rhodes worked in a supervisory capacity, helping Blanch with the high-level mathematical work and checking the work done on the floor. But Rhodes recalled that she spent most of her days tending to the many MTP workers who were living with long-term illnesses or physical disabilities. In her interview for the National Museum of American History, Rhodes recounted, “in the daytime, a great percentage of my time was given over to taking care of these cases. Gertrude and I would begin our work in the evenihuman ng, when everybody left. It was nice and quiet, and telephone didn’t jangle, and people didn’t need our attention.” The MTP provided an accessible place to work and a sense of community and camaraderie for individuals who were physically limited in various ways but mentally quite capable. Rhodes’s experience as a nurse enabled her to look after their physical health, meaning that they could consistently contribute their efforts to the project. At the MTP people with various disabilities gained employment experience, a safe workspace, a sense of belonging, and a social network.

Rhodes argued that the great success of the MTP was not just their extensive and superbly accurate tables but the transformation of these individual lives. Once perceived as “boondogglers,” especially by the scientific establishment, MTP workers gained a sense of accomplishment and support by a social structure, all while doing meaningful work. Rhodes reminisced, “[a]nd, oh – Einstein was telling Dr. Lowan ‘what a marvelous job you’re doing down there!’ But everybody was thinking merely of the Tables. Very few people realized the social work, the… spirit of those people [by] raising them from abject and self-despising people into a team that [acquired] a magnificent esprit de corps.”

Perhaps because the scientific establishment considered the MTP sullied by its association with the WPA, and because its revolutionary human computational efforts were orchestrated by a woman, the project has been long forgotten. But I imagine that for the hundreds of Math Tables Project workers whose lives were transformed and improved by participation in the endeavor and who benefitted from Blanch’s and Rhodes’s diversity of expertise success was far more than just what would be measured or remembered by science.

Further Reading

David Alan Grier, When Computers Were Human (Princeton, NJ: Princeton University Press, 2005).

Kristin Downey, The Woman Behind the New Deal: The Life and Legacy of Frances Perkins – Social Security, Unemployment Insurance, and the Minimum Wage(New York: Anchor Books, 2009).


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