On Saturday (at 9:26:53 to be exact), math lovers and others around the world will celebrate Pi—that really long number that represents the ratio of the circumference of a circle to its diameter. I asked our scientific experts why math is important to biomedical research. Here are a few reasons.

1. Math allows biologists to describe how molecules move in and out of cells, how bacteria shuttle through blood vessels, how drugs get broken down in the body and many other physiological processes.
2. Studying the geometry, topology and other physical characteristics of DNA, proteins and cellular structures has shed light on their functions and on approaches for enhancing or disrupting those functions.
3. Math helps scientists design their experiments, including clinical trials, so they result in meaningful data, a.k.a statistical significance.
4. Scientists use math to piece together all the different parts of a cell, an organ or an entire organism to better understand how the parts interact and how perturbations in these complex systems may contribute to disease.
5. Sometimes it’s impossible or too difficult to answer a research question through traditional lab experiments, so biologists rely on math to develop models that represent the system they’re studying, whether it’s a metastasizing cancer cell or an emerging infectious disease. These approaches allow scientists to indicate the likelihood of certain outcomes as well as refine the research questions.

Want more? Here’s a video with 10 reasons biologists should know some math.