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Expert Tutor: Math, SAT/ACT/GRE/PSAT, SQL, Python, VBA, Excel & Linux
David L.

4.9 (2,119 ratings)

6,183 hours tutoring

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Hourly rate: $28

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About David

Bio

Why I'm a good tutor:
* I know my material. That's how I got a Physics PhD and excelled at software tech support.
* Patience, empathy and praise for my students.
* I love questions: they point to trouble spots. I answer with very specific examples, illustrating general principles and techniques. It's too easy to give too few examples, or leave terms undefined or ambiguous.
* I love teaching and helping people.
* I use my whimsical sense of humor to have fun ("pretend that lumpy thing I...

Why I'm a good tutor:
* I know my material. That's how I got a Physics PhD and excelled at software tech support.
* Patience, empathy and praise for my students.
* I love questions: they point to trouble spots. I answer with very specific examples, illustrating general principles and techniques. It's too easy to give too few examples, or leave terms undefined or ambiguous.
* I love teaching and helping people.
* I use my whimsical sense of humor to have fun ("pretend that lumpy thing I just drew is a circle").
* With math, I write every step on a miro.com whiteboard, which is much better than Wyzant's whiteboard.

I tutor in 3 areas:
MATH
* 18 years of tutoring Algebra 1 thru Calculus.

TEST PREP
* Preparing students for the Math and Science sections of the SAT, the GRE, the ACT, and the PSAT.

SOFTWARE
* I teach complete SQL courses, including joins and subqueries. I have MySQL, PostgreSQL, SQL Server & Oracle servers ready to go, and in 5 minutes, I can get you practicing SQL on SQLite on your computer.
* Python, including web scraping (with Selenium) and working with databases. Sorry, no Data Science or Pandas.
* Linux, Bash scripting, awk, sed, grep & regular expressions.
* I've done many insane things with Microsoft Excel and VBA.

I've been told I'm great at communicating with people at any level of understanding.
I'll put you at ease, and happy to work at your pace.

Here's how many hours I've tutored on Wyzant.com:
Python: 2,086
SQL & Databases: 1,884
Linux & Unix: 515
VBA: 444
Excel (no VBA): 360
SAT Math, ACT Math, ACT Science, and GRE Quant: 317
Math classes, from Algebra through Calculus: 514

For regular or Instant Book sessions, I charge only for the time used, not the time reserved.

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Education

University of California, Los Angeles (UCLA) - BS
Physics
U.C. Berkeley - Physics
PhD

Policies

  • Hourly Rate: $28
  • Rate details: If you postpone or cancel regular or Instant Book sessions nicely, I'll void the charge. Otherwise, I may charge 100%.
  • Lesson cancellation: 3 hours notice required

  • Background check passed on 1/31/2024

  • Your first lesson is backed by our Good Fit Guarantee

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Approved Subjects

ACT Math

ACT Math

I've helped many students improve their scores on the ACT Math & Science, SAT Math, PSAT Math, and the GRE Quantitative Reasoning sections. Sorry, I don't work with the other sections of the GRE or the PSAT. I am very good at teaching and making students feel comfortable. To get great scores, here's what students need: 1. To know the math topics that always appear. 2. To manage your time and solve problems quickly. 3. To know the typical pitfalls and shortcuts. When we are done, you will feel more confident. My work with students is divided into two phases. In phase 1, we go through a practice test together, untimed. When you have trouble with a problem, I'll teach you the math and problem-solving techniques involved. All students have gaps in their math ability. In phase 2, I'll give you some practice tests to take on your own, under simulated testing conditions. Here, you learn how to manage time pressure and how to pace yourself, so you don't spend too much time on some problems. In phase 2, I also ask you to keep track of problems that give you trouble, so we can review them together, to continue improving your command of math and problem-solving techniques. I'm good at helping students who are not native English speakers or who are neurodivergent (ADHD, autism, and dyslexia).
Algebra 1

Algebra 1

I have 15 years of experience tutoring students in math, from pre-algebra to calculus, and in the math sections of the ACT, the GRE, and the SAT. On Wyzant, I've tutored for 518 hours in various topics in math. I've helped math students with a variety of difficulties, such as math anxiety, making lots of mistakes on homework and tests, and teachers and textbooks that were not so good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at a comfortable pace, and good at putting students at ease. When I tutor over the internet, I use an iPad to write on the Wyzant whiteboard. After the session, I can send you screenshots of the whiteboard.
Algebra 2

Algebra 2

I have 15 years of experience tutoring students in math, from pre-algebra to calculus, and in the math sections of the ACT, the GRE, and the SAT. On Wyzant, I've tutored for 518 hours in various topics in math. I've helped math students with a variety of difficulties, such as math anxiety, making lots of mistakes on homework and tests, and teachers and textbooks that were not so good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at a comfortable pace, and good at putting students at ease. When I tutor over the internet, I use an iPad to write on the Wyzant whiteboard. After the session, I can send you screenshots of the whiteboard.
AMC (Competition math)

AMC (Competition math)

I was on Santa Monica High School's math team, and participated in many math competitions, including the 1981 US Math Olympiad. That work laid part of the foundation I used to get my Physics Ph.D. from UC Berkeley. The topics on the AMC were in your high school classes (excluding calculus), plus advanced areas in those topics covered in the book series The Art of Problem Solving. I can give you copies of those books. Free copies of past years' AMC competitions (and solutions) are available online. I use these when tutoring competition math. I also have more than 15 years of experience tutoring students in math, from Algebra 1 to Calculus. If you want to take your math ability to the next level, I'd be happy to help.
Calculus

Calculus

I have 15 years of experience tutoring students in math, from pre-algebra to calculus, and in the math sections of the ACT, the GRE, and the SAT. On Wyzant, I've tutored for 518 hours in various topics in math. I've helped math students with a variety of difficulties, such as math anxiety, making lots of mistakes on homework and tests, and teachers and textbooks that were not so good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at a comfortable pace, and good at putting students at ease. When I tutor over the internet, I use an iPad to write on the Wyzant whiteboard. After the session, I can send you screenshots of the whiteboard.
GRE

GRE

I've helped many students improve their scores on the ACT Math & Science, SAT Math, PSAT Math, and the GRE Quantitative Reasoning sections. Sorry, I don't work with the other sections of the GRE or the PSAT. I am very good at teaching and making students feel comfortable. To get great scores, here's what students need: 1. To know the math topics that always appear. 2. To manage your time and solve problems quickly. 3. To know the typical pitfalls and shortcuts. When we are done, you will feel more confident. My work with students is divided into two phases. In phase 1, we go through a practice test together, untimed. When you have trouble with a problem, I'll teach you the math and problem-solving techniques involved. All students have gaps in their math ability. In phase 2, I'll give you some practice tests to take on your own, under simulated testing conditions. Here, you learn how to manage time pressure and how to pace yourself, so you don't spend too much time on some problems. In phase 2, I also ask you to keep track of problems that give you trouble, so we can review them together, to continue improving your command of math and problem-solving techniques. I'm good at helping students who are not native English speakers or who are neurodivergent (ADHD, autism, and dyslexia).
Linux

Linux

I have tutored 479 hours in Linux, UNIX, Bash, and Bash scripting on Wyzant. I have years of work and tutoring experience with the Linux/UNIX command line and with shell scripting, including with sed, awk, grep, and regular expressions/regex. I have experience working with Ubuntu Desktop and Server, RedHat/CentOS, Kali, and Debian. I have imported and installed a variety of Linux distros into virtual machines in Virtualbox and VMWare on Windows hosts, and have networked together multiple Virtualbox guests running in parallel. I do not tutor C/C++ programming.
Microsoft Excel

Microsoft Excel

I have tutored Excel for 303 hours on Wyzant, not including my VBA tutoring. I have many years of experience with Excel, doing all sorts of insane things with it: * using Solver for the maximal flow, shortest route, and resource allocation problems you see in business classes * pivot tables, including pivot tables of the output of other pivot tables * chains of spreadsheet functions * statistical analyses * charts and tables * custom spreadsheet functions written in VBA * custom windows with hundreds of lines of VBA code. I have a talent for two things: 1) seeing where my students are, and then 2) telling them what they need to know in an easy-to-understand way at a comfortable pace.
Microsoft Windows

Microsoft Windows

I'm an experienced software technical support engineer who has worked with all versions of Windows since Windows 3.11. I have done extensive troubleshooting of problems with the Windows operating system and of programs running on Windows, including problems with slowness, crashing, errors, and malware.
Prealgebra

Prealgebra

I have 15 years of experience as a math tutor, and I've worked with students from middle school through college and beyond, covering topics from pre-algebra and algebra through calculus and linear algebra. I've helped math students with a variety of difficulties, such as math anxiety, a tendency to make lots of mistakes on homework and tests, and teachers and textbooks that were no good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at their own pace, and good at putting students at ease.
Precalculus

Precalculus

I have 15 years of experience tutoring students in math, from pre-algebra to calculus, and in the math sections of the ACT, the GRE, and the SAT. On Wyzant, I've tutored for 518 hours in various topics in math. I've helped math students with a variety of difficulties, such as math anxiety, making lots of mistakes on homework and tests, and teachers and textbooks that were not so good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at a comfortable pace, and good at putting students at ease. When I tutor over the internet, I use an iPad to write on the Wyzant whiteboard. After the session, I can send you screenshots of the whiteboard.
Probability

Probability

I have 15 years of experience tutoring students in math, from pre-algebra to calculus, and in the math sections of the ACT, the GRE, and the SAT. On Wyzant, I've tutored for 518 hours in various topics in math. I've helped math students with a variety of difficulties, such as math anxiety, making lots of mistakes on homework and tests, and teachers and textbooks that were not so good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at a comfortable pace, and good at putting students at ease. When I tutor over the internet, I use an iPad to write on the Wyzant whiteboard. After the session, I can send you screenshots of the whiteboard.
PSAT

PSAT

I've helped many students improve their scores on the ACT Math & Science, SAT Math, PSAT Math, and the GRE Quantitative Reasoning sections. Sorry, I don't work with the other sections of the GRE or the PSAT. I am very good at teaching and making students feel comfortable. To get great scores, here's what students need: 1. To know the math topics that always appear. 2. To manage your time and solve problems quickly. 3. To know the typical pitfalls and shortcuts. When we are done, you will feel more confident. My work with students is divided into two phases. In phase 1, we go through a practice test together, untimed. When you have trouble with a problem, I'll teach you the math and problem-solving techniques involved. All students have gaps in their math ability. In phase 2, I'll give you some practice tests to take on your own, under simulated testing conditions. Here, you learn how to manage time pressure and how to pace yourself, so you don't spend too much time on some problems. In phase 2, I also ask you to keep track of problems that give you trouble, so we can review them together, to continue improving your command of math and problem-solving techniques. I'm good at helping students who are not native English speakers or who are neurodivergent (ADHD, autism, and dyslexia).
Python

Python

Expert, Easy-to-Understand Python Tutor (No Pandas or Data Science) I have tutored Python for 2086 hours on Wyzant, working with students at all levels, from beginners with no programming experience to experienced programmers. I've done a wide variety of Python programming, including many of the basic Python libraries, web scraping (mostly Selenium), database programming, and object-oriented programming. I have 18 years of experience as a tutor of math and software, and 10 years as a Technical Support Engineer. I have a talent for understanding what my students need to know, and teaching them at their own pace. For students with no programming experience, I teach: 1. The basics of Python. 2. The basic programming structures and strategies that people learn with their first programming language. 3. How to understand and fix errors, including basic troubleshooting techniques. 4. How to find Python information and code samples on the internet. I've posted some of my Python programs online on GitHub, at github.com/DavidJLambert. I use PyCharm, Thonny, and Jupyter Notebook, but I'll help you no matter how you write and run Python. I don't teach complete Python classes. I help people who have specific Python questions, or who need help with a Python course they're taking. I teach by programming in small steps. We'll start with a little Python and run it, fixing any issues. In steps, we'll add a little more Python, and run it again, fixing any new issues, until the Python does exactly what we want it to do. Along the way, we'll add temporary print statements to help you understand what the code is doing.
Quantum Physics

Quantum Physics

I've taken Quantum Mechanics courses at UCLA and UC Berkeley. I also took courses in atomic, nuclear, and particle physics courses at UCLA, and one year of particle physics at UC Berkeley. My doctoral dissertation was in particle physics, titled "Study Of b Anti-b Production In e+ e- Annihilation At s**(1/2) = 29 Gev With The Aid Of Neural Networks", using data collected at the Stanford Linear Accelerator Center. If you want help with quantum physics, please let me know what you want help with, and if I can help, we can meet. You should know that there are many misconceptions about quantum physics, and if I you repeat one to me, I will gently tell you how that's a misconception, and I will tell you why.
SAT Math

SAT Math

You can use the powerful Desmos graphing calculator to help you with the SAT Math. I can teach you how to use Desmos to answer many questions much faster than you can do them on paper; while avoiding the careless mistakes you might make on paper. With Desmos, you simply type in an equation, or a system of equations, and see all the solutions graphed out for you. The Desmos calculator can't do everything. You still need to do word problems and understand what the problems are asking you for. You still need to understand all the math topics covered by the SAT. I've helped many students improve their SAT Math scores. I am very good at teaching students and making them feel comfortable with me. To get great scores, here's what you need: 1. To know the math topics that always appear. 2. To manage your time and solve problems quickly. 3. To know the typical pitfalls and shortcuts. 4. To know how and when to use the Desmos graphing calculator. When we are done, you will feel more confident. I help students in two phases. In phase 1, we go through a practice test together, untimed. I'll teach you how to use Desmos. When you have trouble with a problem, I'll teach you the math and problem-solving techniques involved. All students have gaps in their math ability. In phase 2, I'll give you some practice tests to take on your own, under simulated testing conditions. Here, you learn how to manage time pressure and how to pace yourself, so you don't spend too much time on some problems. In phase 2, I also ask you to keep track of problems that give you trouble, so we can review them together, to continue improving your command of math and problem-solving techniques. I'm good at helping students who are not native English speakers or who are neurodivergent (ADHD, autism, and dyslexia).
SQL

SQL

SELECTs with all join types, subqueries, Window functions, bind variables, and SQL UNNEST. I also teach stored procedures & triggers. I have Oracle, SQL Server, MySQL, PostgreSQL, and SQLite databases. I've installed and worked extensively with: * Oracle, PL/SQL, and SQL Developer * SQL Server, T-SQL, and SQL Server Management Studio (SSMS) * PostgreSQL, PL/pgSQL, and pgAdmin * MySQL and MySQL Workbench * SQLite * Microsoft Access (sorry, no forms or reports) I've also helped professionals with Google BigQuery, Snowflake, and Teradata. I've migrated Microsoft's Northwind Database to SQLite, and in 5 minutes I can set it up on your computer to practice on. On Wyzant, I have tutored SQL and databases for 1986 hours. I have 11 years of work experience with SQL and Databases. I've written Python and VBA that generates SQL for interacting with databases.
Trigonometry

Trigonometry

I have 15 years of experience tutoring students in math, from pre-algebra to calculus, and in the math sections of the ACT, the GRE, and the SAT. On Wyzant, I've tutored for 518 hours in various topics in math. I've helped math students with a variety of difficulties, such as math anxiety, making lots of mistakes on homework and tests, and teachers and textbooks that were not so good. I've been told I'm kind and really good at communicating with people at their own level. I'm also patient, happy to work with students at a comfortable pace, and good at putting students at ease. When I tutor over the internet, I use an iPad to write on the Wyzant whiteboard. After the session, I can send you screenshots of the whiteboard.
UNIX

UNIX

I have tutored 479 hours in Linux, UNIX, Bash, and Bash scripting on Wyzant. I have years of work and tutoring experience with the Linux/UNIX command line and with shell scripting, including with sed, awk, grep, and regular expressions/regex. I have experience working with Ubuntu Desktop and Server, RedHat/CentOS, Kali, and Debian. I have imported and installed a variety of Linux distros into virtual machines in Virtualbox and VMWare on Windows hosts, and have networked together multiple Virtualbox guests running in parallel. I do not tutor C/C++ programming.
Visual Basic

Visual Basic

I have tutored VBA on Wyzant for 408 hours. I have taught VBA to lots of people: * many students new to programming, * working professionals needing help with advanced VBA * students doing the Stock Ticker VBA assignment. I've also helped professionals make slow macros run 10-100 times faster. I have written custom worksheet functions, VBA that uses SQL to interact with databases, VBA that uses Selenium to do web scraping, and tons of VBA for custom functionality in Excel, Access, and Outlook, sometimes with custom forms with buttons, list boxes, etc. I only work with VBA and VBScript, not with the .NET version of Visual Basic.

Examples of Expertise

David has provided examples of their subject expertise by answering 47 questions submitted by students on Wyzant’s Ask an Expert.

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Ratings and Reviews

Rating

4.9 (2,119 ratings)
5 star
(1,971)
4 star
(70)
3 star
(33)
2 star
(11)
1 star
(34)

Reviews

An extremely knowledgeable tutor I highly recommend.

David taught me about primary and foreign keys in SQL. He pulled up a database he already had, was ready to teach me to code immediately, and explained everything he did. It was money well spent, and I will continue to learn more and more. I am hiring him again for tutoring. I was thrilled with his tutoring skills.

Consuela, 2 lessons with David

SAT math prep

David has been tutoring my son For SAT math prep. He has been excellent. He is interactive, patient and explains things in a way my son can really understand. Highly recommend him as a tutor.

Jennifer, 7 lessons with David

You're in good hands with, David!

I recently last month started a Linux w/ a Specialized track in Ansible Automation program with a well-known Tech Bootcamp in September. With a background in healthcare, I was completely lost until beginning tutoring with dear, David. He is very knowledgeable in Linux, with his own personal virtual boxes, and knows how to breakdown concepts in a way that are very easy to comprehend and understand. We have had 3 sessions with at least 1 1/2 hours each session and I will have to say I am grasping command concepts, retaining daily user commands, and recently scored a 100% on my project. I will most definitely be continuing tutoring instruction with David in the very near future. You're in good hands with, David!

Lafeysha, 9 lessons with David

Great Learning Experience

I had a great session with David. He was very knowledgeable with SQL, explained concepts clearly, and provided practical examples that made things easy to understand. He was also extremely helpful and accommodating, making sure to address all my questions. Highly recommend working with him!

Amanda, 5 lessons with David

Multiple Column Array

I want to give the highest praise to David L for successfully solving an incredibly complex programming challenge. The task involved building a fully automated data input and output system capable of handling an array of 2,500 rows by 20 columns — no small feat by any measure. Not only did he complete it flawlessly, but he also did it with a level of precision, efficiency, and elegance that exceeded all expectations. David is exceptionally talented. His technical expertise, problem-solving skills, and deep understanding of automation and data handling are truly world-class. But what makes working with him even better is that he’s just a genuinely great guy — patient, professional, collaborative, and always willing to go the extra mile. If you’re lucky enough to have David on your team, you can rest easy knowing the job will not only get done — it’ll get done right.

Jorge , 6 lessons with David

Very patient and knowledgeable tutor

Have been working with David for almost half a year and he has always been punctual, easy to work with and always finds a solution for a problem I have. Highly recommend David!

Tetiana, 25 lessons with David

Best Tutor!

David really helped me when I was in a bind studying Python using Jupyter Notebook. He’s incredibly knowledgeable and was able to guide me through the basics, which gave me a strong foundation to build on. From there, we advanced into more complex topics like Folium. Overall, I couldn’t have asked for a better tutor to help me prepare for my college exams.

Saph, 3 lessons with David

Great Teacher!

Professional and knowledgeable about my excel pivot table needs. Took the time to make sure I understood what I was doing and why.

Tiffany, 1 lesson with David

Knowledgeable & easy to work with

David and I had an in person session on excel. He is very knowledgeable and was able to help me as I explained my very complicated request/need on an excel document. He was able to not only Teach me some really helpful formulas, but we were able to solve my problem. I will absolutely be using him going forward and would highly recommend him!

Vanessa, 3 lessons with David

Knowledgeable & easy to work with

David and I had an in person session on excel. He is very knowledgeable and was able to help me as I explained my very complicated request/need on an excel document. He was able to not only Teach me some really helpful formulas, but we were able to solve my problem. I will absolutely be using him going forward and would highly recommend him!

Vanessa, 3 lessons with David