Online tutoring · Santa Rosa, California
One-on-one tutoring in math, computer science, and physics.
Understand the material, not just the assignment. I'm Marc Klingelhofer — a former engineer and adjunct professor. I work online with high school and college students, one at a time.
High school & college · Online anywhere · Free 1-hour intro session
- 40 years in engineering
- Building real systems at Apple, Intel, Microsoft, Sony, and Sun
- Master's in applied mathematics
- Math used daily on real problems, not left on a shelf
- Adjunct professor
- Taught computer science and college math at Cañada College, Redwood City
- One student at a time
- Every session is one-on-one and built around a single student
Subjects
From first-year algebra through upper-division coursework.
01
High school math
Algebra I & II, geometry, trigonometry, pre-calculus, AP Calculus AB/BC.
02
College math
Calculus I–III, multivariable calculus, linear algebra, differential equations, discrete math.
03
Computer science
Intro programming, data structures, algorithms, computer architecture.
04
Physics
High school and introductory college mechanics.
How it works
Three steps from first message to a standing weekly slot.
Step 01
Free intro session
One hour to talk through the course, get a read on where things stand, and work through some real material together. No charge, and no obligation to continue.
Step 02
A plan
A short written plan: what we cover, in what order, and how we check progress.
Step 03
Weekly sessions
Standing weekly slots, with extra sessions before exams when they're needed.
What sessions feel like
Online, over video, on a shared whiteboard we both draw on. Nothing to install.
Together
We work problems side by side
I don't lecture for an hour. We take a problem you're stuck on and work it out together — I ask more questions than I answer.
Patient
There is no wrong question
"I don't understand any of this" is a perfectly good place to start. Most students have been quietly lost for longer than they'll admit.
Foundational
We fill in what's missing
Trouble with derivatives is often really trouble with algebra from three years ago. We find that gap and close it instead of working around it.
Get in touch
Tell me the course and where things stand. I'll reply within a day and we'll set up a free intro session.
- Based in
- Santa Rosa, California — all sessions are online
- mathbymarc@gmail.com
- Text or call
- (650) 796-7902 — text is the most reliable way to reach me
Common questions
Are sessions online or in person?
Every session is online, over video with a shared whiteboard, so we can work together from anywhere. I'm based in Santa Rosa, California, but students don't need to be.
How long is a session?
An hour is typical. Longer blocks work well before a midterm or a final.
Do you work with more than one student at a time?
Usually sessions are one-on-one. I'll consider a small group of up to three students working on the same material — get in touch and we can talk through whether it's a good fit.
Do you help with homework, or teach ahead?
Both. Most students start with the current assignment, and we build the underlying foundation as we go.
What does it cost?
$50 an hour, flat rate — no packages or tiers.
What does the free intro session cover?
It's a full hour, not a sales call. We check that the online format works for you and the subject, I get a read on where you're actually starting from, and we do some real work together so you can see how a session feels before committing to anything.
Who do you work with?
High school and college students, from first-year algebra through upper-division math, computer science, and physics coursework.
What's the cancellation policy?
24 hours' notice to cancel or reschedule, or 1 hour if you're sick. The first time notice is missed it's just a heads-up; after that it's a $25 fee.
Are you taking new students?
Yes — I'm readily available right now. If that ever changes I'll keep a waitlist rather than turn anyone away.
How do parents stay in the loop?
A short summary after each session — what we covered, what's clicking, and what still needs work — by email or text, whichever you'd rather have.
How do we start?
Get in touch with the course and where things stand. I'll reply within a day and we'll find a time for the free intro session.