Teaching

Concepts first,
computation second.

Instructor of record since 2020 for Calculus II, Calculus III and Linear Algebra, and a full service-mathematics load at Sam Houston State before that. The evaluations below are the university's own reports, shown next to the department averages for the same terms.

Approach

In the room

Draw the theorem

Linear algebra is geometry before it is arithmetic. Working the picture on the board — what the vectors do, what the map does — is what makes the definition stick.

Assessment

Frequent, low-stakes checks

Weekly quizzes that rehearse exactly what the exams will ask, with unlimited-attempt homework carrying worked explanations underneath.

Availability

Reachable outside class

The two items students rate highest are engagement and availability — 4.88 and 4.81 out of 5.0 in Spring 2026.

Student perception of instruction

Every item, against the benchmark.

University of Central Florida SPI reports for both courses. Each row plots my score against the department average for the same term; the axis is zoomed to 3.8–5.0, where all of the variation lives. Underneath each set is the raw response distribution behind those means.

Spring 2026 · MAC2312 Calculus II · N = 16 4.76 / 5.0

Kasun Dewage Department average

Course expectations were clear4.62

The course was well organised4.56

Graded work aligned with content4.56

Clear efforts to engage students4.88

Helpful in responding to questions4.81

Sufficient feedback on performance4.62

Available for assistance4.81

Enhanced my understanding4.69

Response distribution % of respondents

Course and content (Q1–3)4.58

Instructor and instruction (Q4–8)4.76

Full report Comments

Fall 2025 · MAS3105 Linear Algebra · N = 20 4.58 / 5.0

Kasun Dewage Department average

Course expectations were clear4.55

The course was well organised4.30

Graded work aligned with content4.50

Clear efforts to engage students4.70

Helpful in responding to questions4.55

Sufficient feedback on performance4.45

Available for assistance4.55

Enhanced my understanding4.65

Response distribution % of respondents

Course and content (Q1–3)4.45

Instructor and instruction (Q4–8)4.58

Full report Comments

In students' words

Both courses, verbatim.

Free-response answers from the same SPI reports as the charts above. The prompt has two parts — what worked, and what to change — and both are reproduced here, unedited.

Spring 2026

MAC2312 · Calculus with Analytic Geometry II

49 enrolled · 16 responses · 4.76 / 5.0 instructor

Best instructor ever. Love everything you do.
Most effective elements

There’s no way to improve. It’s already perfect like a cheesecake.
Suggestion for improvement

I love him best professor ever
Most effective elements

Always approaching questions with a smile and able to break down any concern into easily understandable pieces; succinctly covers topics in a way that focuses on the most important part: the student's understanding of WHY (derivation, problem solving methods and when/why they're applied) now HOW (memorizing solving methods).
Most effective elements

The course was very clear, and I felt I understood everything by the time we moved onto another topic.
Most effective elements

Telling us what we should remember and how to do “lazy math”. I really enjoyed the availability to help students after or before class. Office hours were very helpful.
Most effective elements

Try to keep the board organized. It was very difficult to understand at first the notes of the class.
Suggestion for improvement

GOATTTTTTTTTT
Most effective elements

GOATTTTTTTTTTTT I LOVE YOU
Suggestion for improvement

The class is hard overall, so his overall positive attitude towards calculus is very helpful
Most effective elements

I wish there was a chance for a deeper/more in depth explanation of the topics, I almost feel like I'm actively attempting to pay attention while also not really grasping the reasons why some things are happening, going through problems initially with the class and explaining why what does what feels like itd be helpful
Suggestion for improvement

I liked your enthusiasm, and I liked the class. The things I didnt like as much are the Knewton alta structure. But I understand it is not really in your control and I would also specifically say the test review assignments in knew alta are not helpful in my opinion.
Most effective elements

I really enjoyed your attitude for the class and how engaging you were. The only thing that I would suggest is checking your email for questions and concerns.
Suggestion for improvement

The instructor really cared about the success of their students and made it a point to help every student.
Most effective elements

Quiz reviews prior to quiz
Suggestion for improvement

Professor was very involved in making sure we were learning the contents of this course. The office hours were a very valuable resource.
Most effective elements

Fall 2025

MAS3105 · Matrix and Linear Algebra

49 enrolled · 20 responses · 4.58 / 5.0 instructor

Amazing theoretical explanations of relationships between concepts and definitions in linear algebra. I love the emphasis on concepts as opposed to computations.
Most effective elements

It is without a doubt that Professor Dewage is passionate about teaching this class and believes in its importance. The homework is very helpful with its examples, unlimited attempts, and explanations.
Most effective elements

Going over the theory in a visualized manner. The drawing it out parts of class really solidified my understanding. I appreciate the few bonus questions given on exams.
Most effective elements

Was very engaging with the class and tried his 100% best when trying to help students with whatever they needed. Explained the concept to the best of his ability. Loved the passion of the professor teaching this content!
Most effective elements

The time given to work on examples written on the board is appreciated, the explanations of concepts is overall pretty good, emphasis on the importance of the subject and its applications is good motivation for learning.
Most effective elements

The class is very hard, however the professor did try his best to make sure students understood and was available for extra help if needed.
Most effective elements

He cared for the students and their ability to succeed in the class.
Most effective elements

The most effective material were the tests. Having 3 tests encouraged studying more of the material than other courses that only had 1 or 2 tests. I found that this motivated me to understand the material much more because of the weight behind it.
Most effective elements

It would be nice if the quiz schedule was loyal to the syllabus, as there sometimes would be quizzes when the syllabus didn't have them listed and vice versa.
Suggestion for improvement

I found that the homework would sometimes show different ways of solving problems then the way that was done in class. Not a huge deal but, it would be easier to follow and learn the material for most if they matched.
Suggestion for improvement

I prefer it when you teach us the topics, theorems and definitions first and then have us do problems, instead of working it out blindly with minimal familiarity and only being told afterwards what it was about.
Suggestion for improvement

The only thing I would change would be the length of the exams as we often ran out of time.
Suggestion for improvement

Appointments and courses

2020 — Present

Teaching Associate / Instructor of Record

University of Central Florida

Instructor of record for Calculus II, Calculus III and Matrix and Linear Algebra
Up to 8 credit hours per semester
Designed lectures, assessments, review materials and structured problem-solving activities

2017 — 2020

Full-Time Lecturer / Pool Faculty

Sam Houston State University

Up to seven mathematics courses per semester, including College Algebra
Curriculum delivery, student support and departmental service
Outstanding Faculty Award nominee, 2019

2015 — 2017

Graduate Teaching Assistant