Calculus Roundtable: Our Staff

Since 2013, Calculus Roundtable has built a community of thousands of supporters around the world. To provide a better experience to students we have assembled a highly effective staff that leads with passion and commitment to improving the lives of students and their families.

Jim Hollis
Executive Director
Jim Is the Director and Founder of The Calculus Roundtable. Jim is a school reformer and a social entrepreneur who has worked with some of this country's largest school districts, as well as some of the smallest. Jim has helped to incubate scores of education startups and consulted with state department's of education on data quality and fiscal planning at the site level. Jim directs the executive functions of the organization as well as the coordination, management and administration of the Integrated Technology solutions and services for schools, districts and foundations.
Jim is the former Director of the Innovation Incubator at Pivot Learning Partners. He's also a founding board member of one of the most innovative charter schools in the Bay Area Community School for Creative Education (the first public Waldorf charter school on the West Coast)

Nina Demediuk
Sr. Project Manager
Nina coordinates our Digital Learning Spaces. Nina is an experienced project manager of hardware and software products in a variety of fields including ed-tech, computer accessories and networking. Nina works with partners and institutions to bring STEM learning spaces to our students.
Nina received BSEE in Electrical Engineering from Rutgers University, and a Masters in Electrical Engineering from the Stevens Institute of Technology.

Chad Reed
After School Coordinator
Mr. Reed is in charge of planning, managing and conducting our enrichment and academic programs for our after school clients in the Bay Area. There are twelve elementary schools, three middle schools and two high schools participating in the program. Chad manages our pool of instructional classroom coaches. His responsibilities include day to day supervision of our coaches, staff training, program development, and working collaboratively with each school site to provide the highest quality academic, enrichment and health activities to the program participant.

Chelanna O'Brien
Professional Development Coordinator
Ms.O'Brien directs our teacher professional development and college fellowship programs. Chelanna has over 20 years experience in public education, teacher and community training on academic, pedagogical, and social-emotional curricula. as a classroom teacher, a professional development coordinator and a systemic school reformer. Erica coordinates our efforts to ensure programs are aligned with our mission and that they make sense to teachers delivering our content in the classroom.

Lesley Pedraza
SBN Project Manager
Ms. Pedraza manages our online education platform, the STEM Broadcasting Network (SBN). Lesley has over twenty year in the photography and production fields.She manages the live class schedules, student announcers, STEM guests and client channel relations.

Gabriella Lora
Special STEM Projects  
Lissette manages our branded assets and collateral materials. Ms Vallejo also serves as an instructional coach for students. Ms Vallejo received her bachelors degree from UC Berkeley in Landscape Architecture.

Traye Turner
Instructional Coach 
Traye coordinates our coding and computer science instruction and course work . Mr. Turner previously built and tested games for PlayStation and Sega . Mr. Turner has a bachelors in computer art from the SF Art Institute 

Calculus Roundtable Diversity in STEM Fellows

2nd Year Fellows

Darnice Davis
Darnice is a civil engineering student currently attending San Francisco State University. Darnice works as a math tutor and instructional coach in our 'Girls Math Club. Ms Davis received her AS from Chabot College in Mathematics. Ms Davis is an active member of: National Society of Black Engineers Society of Women in Engineering and the American Society of Civil Engineers

Juan Cardenas
Juan is a Mechanical Engineering student at University of California in Berkeley. Mr. Cardenas is studying Nanotechnology and biomechanics. Juan works as a math tutor and instructional coach in our Digital One Room Schoolhouse (DORS) Program Mr Cardenas was elected Valedictorian of high school in Los Angeles
More on Juan

Aldo Gonzalez Ruiz
Aldo is a Mechanical Engineering student at University of California in Berkeley. Mr. Gonzalez-Ruiz works as a math tutor and instructional coach in our Digital One Room Schoolhouse (DORS) Program.

Briana Santana 
Brianna a Electrical Engineering student currently attending University of California in Los Angeles. Brianna works as a math tutor and instructional coach in our 'Girls Math Club'.

Valeria Landeros
Valeria Landeros is an undergraduate student majoring in EECS at the University of California, Berkeley. Valeria grew up in the community of South Central, Los Angeles and graduated from John C Fremont STEAM Magnet High School. With her EECS major and neuroscience minor she wants to obtain experience and research AI technology and give back to her own community back in LA.

John Zelaski
John is a graduate of Xavier University of Louisiana with a degree in biology and Pre-Med with Minors in Spanish & Chemistry. John work with our Bio-Med and Sports Math programs in Richmond and San Leandro, CA.John has been a PAC-12 NCAA football player, an oncology researcher and an HBCU graduate.
John is a member of the prestigious Louis Stokes Louisiana Alliance for Minority Scholars and a ,member of Sigma Alpha Pi.

1st Year Fellows

Samara Tana
John is a graduate of Xavier University of Louisiana with a degree in biology and Pre-Med with Minors in Spanish & Chemistry. John work with our Bio-Med and Sports Math programs in Richmond and San Leandro, CA.John has been a PAC-12 NCAA football player, an oncology researcher and an HBCU graduate.
John is a member of the prestigious Louis Stokes Louisiana Alliance for Minority Scholars and a ,member of Sigma Alpha Pi.