Faculty

Zack joined Tilden in 2017 and  has been educating youth for over seventeen years having previously operated a private tutoring business in Marin County with an emphasis in math and science, run a robotics camp for middle school students in Berkeley, and taught math in a private high school in San Rafael. Zack has a love for math and science, which he enjoys passing on to his students. He earned his B.S. in Bioresource Sciences at U.C. Berkeley and went on to complete graduate coursework at U.C. Davis in anatomy and physiology. Zack also teaches sailing for Cal Adventures in Berkeley and has taught downhill skiing for Squaw Valley USA.

Zack Alexander, B.S., Math Department Head - Lead

Aynealem Goitom Berhe is from a small country in the North Horn of Africa by the Red Sea. He received his BS and Master's degrees in Marine Biology, and teaches both Math and Science courses. In his free time, he plays volleyball and is a certified diver -- he enjoys diving more than any other recreational activity, especially if the waters are tropical and inhabited by coral reefs and coral reef fish. He also enjoys cooking Eritrean and Japanese cuisines and can speak multiple languages; Japanese and Tigrinya are two of them. Aynealem joined the Tilden faculty in 2021.

Aynealem Berhe, M.S.

Marta has a B.A. in English from Lewis and Clark College in Oregon, with a minor in Classical Studies. She continued studying Classical Studies at the graduate level, but realized that her passion was in education, and spent several years tutoring and teaching English, history, and math to middle and high school students before joining the Tilden family in 2017. She has a teaching credential in English, and believes that all students are capable of becoming strong readers and writers with the right support and guidance in finding the stories they love. She also enjoys delving into the depths of history to find the reasons behind any given event, and does her best to share the most interesting historical details with her students (and anyone else who will listen). She teaches English, history, social sciences, and Latin. In her spare time, she likes reading, drawing, and tabletop gaming.

Marta Blanchard, B.A.

Pamela is a native New Yorker, but has spent most of her adult life in the Bay Area. She earned a B.A. in English Literature/Writing from Rider University, and an M.A. in English Literature from Rutgers University. After moving to the Bay Area, Pamela began her career as an educator teaching English and Humanities at private middle schools and has served as an Assistant Head of School as well. Pamela joined Tilden’s faculty in 2021. A life-long learner, Pamela attended Mills College and earned a Masters in Educational Leadership. She is in the process of completing her dissertation in the Ed.D. program at Mills College- Northeastern University. Her philosophy of education values the mind,the heart and progressive pedagogies. She believes that her mission as an educator makes it possible for students to become themselves and find their individual voice. Pamela is a Bay Area Writing Project Consultant and a member of the Facing History and Ourselves ELA Advisory Board. On weekends, Pamela loves to walk the many beautiful trails in the Bay Area.

Pamela Brenman, M.A.

Miguel previously worked as a Math Empowerment Teacher for the nonprofit organization Making Waves Education Program located in Richmond, CA. Here he supported low income students in a one-to-one setting. Miguel found Tilden’s Prep model to be nearly identical to that of his previous job. Intrigued with this similarity, he started teaching at Tilden Prep in June, 2013. Miguel holds a B.S. in Mechanical Engineering from UC Berkeley and teaches a variety of courses including math through Calculus BC, chemistry, physics, and computer science. In his spare time he works as an online math curriculum developer and webmaster for "MathFortress.com", an educational website that he created for the purpose of expanding his reach to a greater audience via unique video tutorials for various mathematical disciplines.

Miguel Chan, B.S.

Keiko was born and raised in Tokyo. She started tutoring middle and high school students while in college, and following graduation, taught English and later became certified as a Japanese language teacher in Japan. She started teaching Japanese at Tilden in 2007, and has enjoyed teaching from Japanese 1 through the AP level to many students. She also enjoys watching Japanese anime, drama, and movies. In her spare time, Keiko enjoys flower arranging, and is a licensed teacher of Ikebana (Japanese flower arrangement).

Keiko Endo

Bjorn Fox has an undergraduate degree in Mechanical Engineering from San Francisco State University and a Master's Degree in Management from Cal State East Bay. Bjorn has one year of experience working as a substitute teacher in small to medium sized classrooms and experience as a tutor. He joined the Tilden team as a math and science teacher in 2022. 

Bjorn Fox, M.A.

Ben Graber was born and raised in Berkeley, California.  Ben received his AA degree from Laney College. He received his BA in History and American Indian Studies from San Francisco State.  He went on to complete his MA degree in U.S. History with a specialization in Race and Gender in the 20th Century United States.  He has done extensive Oral History with tribal nations across California including the Pomo, Ohlone, and Mojave peoples.  Ben has presented academic papers at the Human Rights Conference in San Francisco and the California Indian Conference.    He was a frequent guest lecturer at SFSU and a history professor at the University of Phoenix – Bay Area campus for more than seven years. Ben also speaks Spanish and does volunteer work in Spanish-speaking communities in the East Bay.  He has also tutored math, astronomy, geography, and test prep for the GRE, SAT, ACT, and GED exams. Ben joined Tilden in 2020.

Ben Graber, M.A., English and History Department Head

Rachel graduated from San Francisco State University with degrees in Marine Biology (BS) and Ecology and Systematic Biology (MS). From there, she continued her research at UC Davis in the Geology department with a concentration in Paleobiology. Before coming to Tilden in 2017, Rachel worked in the public programs department at the Exploratorium and deep in the shelves of the Invertebrate Zoology and Geology collections at the California Academy of Sciences in San Francisco. She has a life-long dedication to inquiry-based science and exploration of the natural world. When she's not at Tilden, Rachel enjoys open-water swimming in the Bay, sailing, drawing, and experimenting with fermented foods.

Rachel Hertog, Ph.D., Science Department Head

Claire grew up surrounded by good books & music in San Diego. As an undergraduate, she studied interdisciplinary humanities; she also adored working at the art museum and as an art history TA. After college, Claire adventured toward New Mexico; high desert magic blossomed into years working as a massage therapist and bodywork instructor. Claire returned to a formal study of philosophy and literature at St. John’s College in Santa Fe, where she earned a Master of Arts in Liberal Arts in 2022. She and her beloved spouse Travis moved to Berkeley this summer with their raucous kitten, Marigold. Some of her literary soul-friends include Emily Dickinson, Virginia Woolf, and Clarice Lispector. When she’s not reading, Claire can be found sunbathing, playing the piano, hiking, baking unexpected treats, watching a Bergman film, or singing with the San Francisco Bach Choir. Claire is thrilled to be learning alongside Tilden scholars starting in 2022!

Claire McMahan-Stackow, M.A,

Xuannga “Sonia” Mahini is a graduate of the University of California, Berkeley, with a BA degree in Biochemistry and a Master of Public Health (MPH) degree. Prior to joining Tilden Prep in 2021, she worked for various national and international environmental consulting firms and the Electric Power Research Institute. In her role as Regional Director, Manager, or Principal, she has trained numerous chemists, engineers, environmental professionals, and toxicologists to perform comprehensive risk assessments for the protection of public health and the environment. She enjoys tutoring her son and his friends in all subjects, as their needs arise. She is currently living in Berkeley with her family and enjoys cooking, gardening, home construction, designing jewelry, sewing, and taking care of her aging neighbors.

Sonia Mahini, M.P.H.

Aicha is a mom to two beautiful, creative young adults. She worked on art projects with preschoolers to high school seniors, actively helped organize, photograph performances, field trips, camps, concerts, art projects, fundraisers, cook outs, drama productions. Aicha was  a volunteer trip leader for people with disabilities and under-resourced youth with ETC's winter ski program. She speaks several languages and has lived on four continents; Aicha enjoys most people and appreciates quirkiness and originality in others. She is passionate about photography, and specializes in triptychs. Her work is collected by art collectors, clients and friends all over the planet. Aicha has B.A. in architecture with a minor in photography and sculpture from Pratt Institute, studied photography at Camera Obscura, political science at the University of Tel Aviv, and enjoyed woodworking classes at Laney College. She loves to live, cook, eat, hike, kayak, travel, learn new things, build and be with her family and friends. Aicha joined Tilden teaching art and photography in 2022. 

Aicha Nystrom, B.A.

Tonantzin (Toni) was born and raised in Mexico City, where she received a Bachelor's in Special Education, with emphasis on Speech, Language and Hearing Impairments. She worked as a special education teacher and consultant for many years. She also taught college level courses in various universities and teacher formation programs in Mexico City. In 2000, she came to the United States as a foreign student to pursue a Master’s in Special Education from Cal State University, Sacramento. After moving permanently to California, she switched careers to teach Spanish and holds a Single-Subject teaching credential in Spanish. She joined Tilden Prep from 2012 to 2014, and she returned in 2021. She enjoys sharing with students the love for her language and culture. She also teaches at Albany Middle School. Married to a Bay Area native, she lives in Albany, where she and her spouse have raised two daughters.

Toni Martinez-Borgfeldt, M.A.

Shanah is a Hebrew word meaning 'year' or 'to repeat again'. She is a mathematician with a Master's degree in Applied Mathematics from Cal State East Bay in Hayward. Mathematics is her passion and has shaped her entire life. Shanah has been working in the field of math education for almost 11 years now and has been a teacher for five years prior to joining the Tilden faculty in 2022. She also teaches Math and Coding part-time at Mills by Northeastern University in Oakland twice a month for their Upward Bound program for youth. Her teaching philosophy states that every student, when given the opportunity and resources, can become mathematically literate. Most of Shanah’s hobbies are centered around promoting her mental well-being and include kayaking, gardening, painting, baking, singing, and cooking. 

Shanah Richardson, M.S.

Ana Tafur is a Spanish and Latin American literature teacher  She graduated from University of California, Davis. She has taught Spanish and Latin American literature to students of all ages for the past fifteen years. In her spare time Ana enjoys cooking, reading poetry books, watching documentaries, learning Portuguese and walking in nature with her husband and her mini Shnauzer Pandita.

Ana Tafur, B.A.

Christina is a Bay Area native who earned a B.A. in Sociology from Loyola Marymount University in Los Angeles and after graduating applied for a Fulbright Scholarship to teach abroad in Thailand. When she was not granted the scholarship, she worked and saved for a year, then booked a one-way ticket to Bangkok, which turned into five years of teaching English in Thailand and Japan.  Ask Christina for thoughts on books, post-modernist social or philosophical theory, psychology or simply a good travel story. Her favorite part about working with young learners is seeing their potential and helping to cultivate it, not impinge upon or restrict it, as she knows there are many ways to foster success and curiosity in the world. Upon returning to the Bay Area, she joined the Tilden faculty in 2017.

Christina Tenuto, B.A.

Willis is a Human Physiology graduate from the University of Oregon who joined Tilden in 2021. Prior to working at Tilden, he was a surgical assistant at a private Plastic/Reconstructive clinic and registered EMT. His attention to detail and ability to pick up on cues and opportunity comes from his medical experience and consistently applies it for his students' benefit in lessons. He has a passion for teaching and unveiling to students that their potential for learning can be far greater than they expect at times.

Willis Back, B.A.

Josiah graduated from UC Davis with a B.S. in Neurobiology. He started tutoring during college in math and science for students with disabilities. He then went on to teach middle school math and science. Josiah enjoys teaching math and science because they help us understand the world we live in. His hobbies outside of work include reading, hiking, camping, and fishing.

Josiah Barron, B.S.

Originally from Ethiopia, Fassil came to the U.S. after finishing high school and is now a naturalized U.S. citizen.  He holds a Bachelor's degree in Mathematics from the University of Chicago, with a minor in Statistics.   He has also done graduate studies in mathematics at Cornell University and holds a Master's degree in Computer Science from Cornell.   Fassil has worked extensively in the financial services industry in New York in various capacities as an analyst, software developer, and  manager.   He loves mathematics, enjoys teaching, and has taught for over ten years.  Fassil has a talent for strategy board games such as checkers, chess, shogi and go and is rated amateur 3-dan in shogi.  Among the things he currently likes to do in his spare time is watching chess engine  competitions.   He enjoys Japanese enka songs, traditional Korean music, opera, and a variety of other music.

Fassil Bekele, M.S.

Reed holds degrees in Mathematics, Computers and Electrical Engineering from the California Institute of Technology and UC Santa Barbara. He has used his science skills as a space engineer, designing satellites, as well as balancing these left brain activities with surfing, music, dance and other more right-brained, artistic and athletic explorations. At Tilden, Reed helps students to break down abstract math or science concepts into their simplest essence, so helping students to achieve mastery whether math and science come easy to the student or not. Reed believes that there are as many different ways to learn as there are people, and that the key to learning is really as simple as a motivated student and an inspiring, caring teacher.

Reed Burkhart, M.S.

Tim obtained a Bachelor of Science degree in Physics and a Bachelor of Arts in Computer Science at UC Santa Cruz. He joined Tilden teaching math and science in 2022 after previous experience as a substitute teacher and a tutor. Tim likes teaching one on one to greatly assist students in how to think, learn and program. 

Tim Burkhart, B.S., B.A.

Cliff was born and raised in Mexico City until the age of 11. His family decided to move to the United States to seek better education opportunities for his brother and him. While attending College Park High School in Pleasant Hill; Cliff discovered that he had a passion for teaching and helping others with class work. Throughout his high school years, Cliff, his best friend Matt, and his brother held tutoring sessions during lunch in math, French and Spanish. During High School is when he knew he wanted to be a professor/teacher. After high school, Cliff went off to college and received a degree from U.C. Berkeley in Spanish Literature and Language. A couple of years later, he completed a Master's program at San Francisco State. Cliff has tutored middle school and high school students for over 15 years and has taught college level courses for 5 years at D.V.C, St. Mary’s College, and Holy Names in Oakland. When Cliff is not working at Tilden or at one of the colleges, he loves going to the movies and traveling. He spends too much time at the movies!  Another fun fact: he and his brother are twins.

Cliff Escobedo, Foreign Language Department Head

Farhad has a Bachelor of Arts in Biology, and is currently pursuing a Master’s of Science in Physics at San Francisco State University. He has a notable interest in medical physics, and has published work in diagnostic radiology. He also has research experience in chemical ecology, soil science, and plant pathology, at UC Davis and UCSF Medical Center. Farhad became part of the Tilden faculty in 2022 teaching math and science. He is also a bibliophile, particularly in the realm of philosophy and anthropology. Farhad also spends a lot of time playing beach volleyball on a competitive basis, and coaching for various skill levels.

Farhad Fazel, M.S.

Claire is a French native who studied business, followed by math and physics, in France. She holds a M.F.A. in Studio Arts from Towson University, MD, and her work has been extensively exhibited on the East Coast, in Illinois, Texas, New Mexico, and Scotland.

From figurative paintings to abstract drawings or installations, her work explores the unspoken, the ignored, and the power of silence. Claire carefully chooses her mediums for their emotional, historical and cultural values, or the implied meanings of their physical properties.  Prior to moving to California, Claire was a lecturer in French and an Adjunct Professor in Visual Arts at Towson University in Maryland and the University of Baltimore. She teaches French at Tilden Prep, and loves sharing anecdotes about the French language with her students. Claire enjoys learning about anything and everything, and in her free time, you will find her outside reading, gardening, hiking, or working on some project.

Claire Girodie, M.F.A.

Susana earned her degree in Earth Science from UC Santa Cruz. She previously worked as a former physics and math tutor at Los Medanos College for STEM majors. She also has previous experience working with middle and high school students as a private tutor. Susana formulates her lessons to best suit the student's individual needs. Susana believes students need repetition, encouragement, and constant participation in order to feel the desire to learn. She also believes that learning is a physiological activity which involves the body as a whole. Susana loves drawing and hiking as she enjoys being outdoors in nature. She has run the Mt. Diablo Summit twice. Susana teaches math, science, and foreign language.

Susana Maltez, B.S., Science Department Head

Cerys Morgan holds a degree in Statistics with a minor in Ethnic Studies from University of California Berkeley. After working as a research assistant at the Data Science Institute in London, England, she realized she wanted to put her knowledge to good use and became a tutor in both math and English. She believes that the connection a teacher has with a student can create a passion or interest in that subject and that teachers have a real place to make a change in the world. Being capable of teaching both math and English, she was able to help create a curriculum for a reading program upon her return from the UK. She strives to bring some light, organization and positivity to the Tilden Team. Outside of school, she loves to spend time with family, travel back to the UK to see her mother, grandmother and friends, as well as loves to spend time finding new and interesting shows on Netflix

Cerys Morgan, B.S.

A Bay Area native, Ricky has a strong connection to and love for his community. Formerly pre-med, Ricky attended both Los Medanos College and UC Davis before graduating with his B.S. in Biochemistry from CSU East Bay. In addition to formerly tutoring both junior high and high school students, Ricky also tutored college students in math, engineering, and science. Ricky is passionate about teaching students and helping them achieve their educational goals. In his spare time, Ricky enjoys giving back, volunteering at convalescent homes, playing guitar and singing for residents. Ricky also coaches a Bible Quiz team at his local church. Spending time with friends and family, Ricky is always up for a good board game or a trip to a local frozen yogurt shop.

Ricky Munoz, B.A., Math Department Head

Andrew is a Bay Area native with a lifelong interest in reading history, something he picked up from my father. This hobby later led him to attend UC Santa Cruz, where he received a BA in World History, followed by a Master's Degree in American History at San Jose State. His teaching credential was granted in 2007 from Dominican University. Andrew has had a varied teaching career. He spent three years working for the Oakland Unified School District, followed by a seven year stint teaching in China. In China he worked at a college prep high school for high achieving students who wished to study in American Universities. His main focus was American History, both as a survey course and AP. He was proud to help students get accepted to universities such as UC Berkeley and Princeton, among others. Upon return to the United States, he taught for another year in Oakland, as well as working for the Cabrillo Unified School District in Half Moon Bay. He is happy to be back teaching motivated students in a college prep setting at Tilden Prep. The one to one model allows for a unique teaching experience that genuinely caters to the needs of each student. He is finding it to be a rewarding new challenge. Andrew currently lives in Berkeley, with his wife and seven year old daughter.

Andrew Odgers, M.A.

Will joined Tilden’s faculty as a math, science, and humanities teacher in 2022. Will majored in Philosophy at UC Berkeley after having achieved his Associates degree in Chemistry. Will had previous experience as a tutor. 

Will Ranney, B.A.

Anthony graduated from the University of San Francisco with a Bachelor of Arts in History. Prior to coming to Tilden in 2021, he worked at the Museo Italo Americano as a research assistant and for two years with Pleasanton Unified School District. During that time, Anthony tutored AP history. He is a lifelong learner and hopes to share that with the students at Tilden. 

Anthony Sabatini, B.A.

Christine is a Bay Area native who received a BA in American Studies and Peace Studies from the University of Notre Dame. She previously taught at a small Catholic high school before coming to Tilden in 2019. In the classroom, Christine enjoys helping students think critically and make connections between the concepts on the page and their lives. Outside of the classroom, Christine enjoys cheering for the Fighting Irish, writing, movie comedies, and trivia contests. Christine teaches humanities at Tilden.

Christine Schreck, B.A., History & English Department Head

Joseph graduated from UCSC in 2016 with a BA in English Literature. He really enjoys teaching and that is mainly what he has been doing since graduation. Joseph’s hobbies include: hiking, playing guitar, reading novels, and learning foreign languages. Joseph became part of the Tilden faculty in 2018 where he teaches humanities.

Joseph Vincent, B.A.

Cristian was born and raised in Viña del Mar, Chile, a city by the beach. There he obtained his degree in Education and a major in English Pedagogy at Saint Thomas University. Cristian has always been a very passionate person, especially in sports and music. During his childhood, he was part of his high school’s soccer team and was awarded as top scorer of the tournaments multiple times. Cristian also taught himself to play guitar and performed in a band. At the age of 22, he became an English Teacher. One week after his graduation, he started working as a head teacher of a 6th grade class at a very prestigious school from his hometown. After three years of teaching English as a foreign language, Cristian moved to the United States where he has been working as a Spanish teacher and tutor.  He joined the Tilden faculty in 2015. Cristian is a very dedicated teacher who focuses his teaching style on helping students believe in themselves by using their strengths and working hard to improve their areas of need. As a Tilden Prep Spanish teacher, he is willing to give a 100% in order to assist students in achieving their individual goals and objectives. When Cristian is not working, he loves spending time playing music, singing, playing tennis and soccer, and spending time with family.

Cristian Vera B., B.A.

"I wish that traditional schools would look at the Tilden model, so that more kids would have a chance to succeed at school."

Tilden Parent