Correlation and Causation

On Chapter 3, we earned about correlation. In this chapter, I it was a bit difficult to catch up because there are so many calculation and keywords relate into this. It is a really fun topic to learn, and see the association between two variables. We did a small project where we survey Liger students and we compare those data to see are there a correlation. It turns out that height and weigh have a high correlation. 

Correlation (r) has a range from -1 to 1; when r = 1 or -1 means that two variable are really correlated but that does not means that one causing another. Correlation means that the two variable have an association; causation means that one causing another to happen, we can conclude that only if we do the experiment.

This an example of two unrelated variables, but they do have a high correlation. This doesn’t means that eating mozzarella cheese cause you to have a civil engineering doctorates awarded. Source:


S’mores Lab

Part of our chemistry class, in term three, we learn about chemical reactions and determine bonds types. When we learned about determine bonds type, everyone in the class perceives the information quickly — because of our teacher! When it comes to chemical reaction and calculating excess reactant or limited reactant, most of us was froze. However our facilitator, Ellie, assigned us to do a lab where the product is s’mores.  From that lab we need to calculate the limited reactants and the excess reactant. For me, I learn each ingredient of s’mores and I can implement it into the actual chemical. I better understand of calculating chemical reaction better than just learning it theoretically.

Image result for s'mores
Picture of a s’more. Image from:


Lab Report

Problem:  Given a certain quantity of marshmallows, graham crackers, and chocolate pieces, what is the maximum number of S’mores that can be made?  Then figure out your percent yield!

Substance Symbol
Graham Cracker (half of a cracker) Gc
Marshmallow M
Chocolate Piece (individual piece of chocolate) Cp
S’more  (2 crackers, 2 pieces of chocolate, 2 marshmallow) Gc2MCp2


  1.  Use the 3 different reactants and one product to write a balanced equation for the making of s’mores

                            2Gc + 2M  + 2Cp → 1Gc2MCp2  

  1. What type of reaction would this be classified as? Both chemical and physical reaction
  2.  Record the total moles (pieces) of each reactant available at your table

Graham Cracker (Gc)-  6 Marshmallow (M)-  8       Chocolate Pieces (Cp)- 6

(amount of halfs of Gc) (each single marshmallow) (each single chocolate piece- 12 per bar)

  1. What is the maximum number of s’mores that your group can make?   3 s’mores

Why? The reason that we can make 3 s’mores because we got 6 mol Gc, 6 mol Cp, and 8 mol M, and for 6 mol of Cp we can only make 3 s’mores.

Which reactant/s is/are limiting?  (the one/s that you will run out of first) : Gc and Cp

Which reactant/s is/are  in excess (the one/s that will be left over) M

  1. Find the mass of one of each of the individual reactants (first zero a napkin and then find the mass on top of the napkin)

Graham Cracker (Gc)-  7.9 g Marshmallow (M)-  3.8 g Chocolate Piece (Cp)- 2.9 g

(one halfs of Gc) (one single marshmallow)           (one single chocolate piece)

  1. Record the theoretical yield/mass of a S’more (Gc2M2Cp2) using your reactants (you can add them together) = 29.2 g
  2. Make your s’mores
    a. Make sure that you follow the chemical reaction equation and get all of the reactants ready.
  3. roast your marshmallows over the Bunsen burner using a skewer. And then make your finished product.  
  4. Before eating your s’more find the actual mass (yield) of your s’more

(put a napkin on the scale, zero the scale and THEN put on your smore).

The ACTUAL (experimental) mass of one s’mores: 29.0 g

  1.  Find the percent yield of your s’mores: 29.0/29.2 * 100 = 99.32 %   Theoretical yield = from part 6 Actual or experiemental yield= from part 7c

percent yield= 99.32%

  1. How did you know which reactant was limiting?

Graham Cracker and Chocolate Piece are the limiting reactants. Based on the chemical equations, to create a s’mor  we need 2Gc, 2M, and 2Cp; we got only 6 Cp and 6 Gc and 8M. When we divide all reactant by 2 there’s no remaining for Gc and Cp, but remaining 2M. From the arithmetic, we can see that Gc and Cp runs out first — so they are the limiting reactant.

  1. How did you figure out the excess reactant?

We know that Marshmello is an excess reactant because we need only 6 (based on the common factor of the limit reactants) to create 3 s’mors, but the total marshmello is 8. This leave a remaining of 2 marshmallows. Also during the experiment, we followed the chemical reaction equation and turned out that there are two marshmallow left over.

  1. How did you figure out your theoretical yield for your product?

We weigh all of the reactants: Graham Cracker (Gc)-  7.9 g, Marshmallow (M)- 3.8 g, and Chocolate Piece (Cp)- 2.9 g. We take each reactant multiply by 2 (based on the equation) and sum it all up; we got a total of 29.2 g per s’mor.

Chemistry Round 1

This year of Liger we started to have a chemistry built in our essential. I found out that I do like chemistry, especially learning about the atoms. This term, we were learning the introduction of chemistry: Matters, Mole and Molar mass, Periodic Table, Atom Structure, Electron Configuration, and Valence Electron. The topic that I think it was struggling for me is the Electron Configuration. Moreover, we did a lot of experiments: Coin Density, Liquid Density, and Flame Emission.

The picture was taken after the flame emission lab.

The most interesting lab was the Flame Emission! For this experiment, we try to burn many types of salt like Copper (II) chloride, Lithium Chloride, Potassium Chloride etc. Each of these salt emits a different type of color: for Copper (II) Chloride emits cyan light. It was a really fun experiment that I ever have out of other experiments.

For my final project of the round, I did a presentation that explains to the class about the Electron Configuration. I choose this topic because it was a difficult topic to understand, so I just challenge myself to do it. It turns out that I did it very well, my classmates asked me more questions about the topic and I got 1 bonus point!

If you want to see more of my presentation:

SAT Preparation

The SAT is in the 2 weeks and I still have no idea of what’s going to happens. Everyday in math class, we had about 30 minutes of class time to work on math section. I don’t think I have enough time to do it! Every students in the school require to practice out side of class time 30 minutes to 1 hour each day. SAT is not the only thing that depict us how smart we are, but for students who want to go to university at America, we need to do it!

During the summer holiday, I spent most of the time practicing the SAT and I did get some good result out of it. I know that the only way to get better is to practice; you need to practice every day! I felt better when I’m at home practicing, but when I’m in school, I don’t feel good about it because of my busy works. 

To be honest, I don’t really practice SAT that much, but in the next two weeks, I will deadly practice it every single day. I know it a procrastination, but practice for 2 weeks is better than practice nothing. 

We use some resources like Khan Academy, textbooks, and college board website. Those resources help me to gain confident little by little. I feel anxious about the upcoming SAT; I hope I do it well.


Collage Board Example Questions! Link:
Khan Academy practice questions! It about congruence and similarity. Link:
Khan Academy alerting system, where it reminds us everyday to practice SAT. I found it very useful because it reminds me to always think about SAT.

Basketball Competition 3×3

My first event for in this seventh year of Liger is basketball game. The Cambodian Basketball Federation hosted a FIBA 3 on 3 competition U18. The competition requires 2 boy and 2 girls in a team. I am interestin in basketball, so I brought two teams from Liger to participate in the competition. The event hosted in a stadium that looked really epic! It was a national stadium, and it appealed beautiful with the lights. I wish to play on those kinds of the field, and I did.

Before the game, there was an opening game where people with diability play basketball with each other.

The game went really well, the teams our group was really advanced. We won the first game; we were really happy with the result. It was scary to play on the field; I missed a lot of layups. In the second game, it was extremely hard, there was a guy who is a 3 pointer and he was really good at it. The result was lost! We need to win the third game in order to move to the next stage and we played with another great team who’s players are in the national team. We tried our best to compete with them but we just not good enough to beat them. And we lost again! 

So we just kissed the knockout stage and went home. But at the final stage, the teams that we lost were played with each other again. It was really a powerful experience to me. I now know where am I and I learned a lot of others moves. I love this event and I hope they would host it every year!

This is how the stadium looks like!
This is everyone who participated in the event!


SAT Boot Camp

It was my last day of the summer break, and I felt like time was running really fast! I enjoyed my last day by riding a bike to an open rice field and indulge myself with the sunset.  The next day, I arrived Liger and feeling sad about seeing my parent went home. opposite of that, it was a new year, new apartment, new roommates, and new school year. I felt really ready for the first class of the year. 

Guess what, we start the class with a PSAT test! It was really funny to me and it turned out that I did pretty well on it. So our first two weeks of Liger, we started with the SAT boot camp. Our exam will be in the next one month and a half. To be honest, the boot camp was really boring but we just need to face it! We learn many strategies to take the test and it was really helpful! Every student endeavored to finish the intense homework that was given — some of us would be sleepless. Moreover, in that two weeks, we took three PSAT test which is about 12 hours in total. It was really suffering and fun experience with this beginning of the year!  

Full tests:

This is an example of a technique that uses for implicit and explicit questions in the reading section of the SAT. 



The writing section of the SAT.
That was a group photo with our mentors in the middle.

Changing Cambodia: 2017-2018

Changing Cambodia 2017-2018

My life this year started, “Be the change you want to see in the world” (by Mahatma Gandhi). This quote guided me to travel through the rest of the school year at Liger. My ambition was to create positive changes to this country, Cambodia; I want to see changes, and to see Cambodia becomes an outstanding country from other nations around Southeast-Asia by the time I reach my life-retirement. From this ambition, I deemed to take agencies in my life this year. I have accomplished and dispatched in many events: engineering internship, robotics competition, took an AP computer science exam, and give Ted Talk. My next stride will be full of dust and snow, the path will be illusive I do not know what will be happen next, all I knew is Cambodia needs improvement on technology field.

It is my second year of high school, life is always occupied with works. The year began, I realized that in order, “To move the world, we must move ourselves”–Socrates. The two quotes above motivated me to build up my self-esteemed in creating positive changes to Cambodia and to myself. As the passion built up, I began my first step: summer internship.

From years to years, Cambodia takes a very big leap in its engineering field. Based on GeeksinCambodia published in 2015–a news website about technology in Cambodia–has stated that 90 percent of the population each own a mobile phone. The data clearly demonstrates that the majority of the population in Cambodia have access to technology. Our government attempt to do their best to grab its citizens attention on technology by promoting through STEM Festival, Maker Faire, and other collaborative events. These events ruffled numerous of change-agents to get involved into technology: I then knew Arrowdot.  

That was when I move myself!

I spent my summer-break mainly on internship at a startup called Arrowdot. During the internship, I had experienced how the society works in Cambodia. I learned to manage my own budget, transportation, and food. It was the moment where collaboration with university students and I initiated. In the internship, it was an elusive advantageous to help the company while enhanced myself. At Arrowdot, one of the missions was to give extra class to university students. My responsibility in the internship was to setup the plan for the experiments.

That responsibility required me to be familiar with the concept and turn it into an ecstatic experiments. To be honest for some labs, it took me a bunch of time to get it done: the labs was sophisticated for me. The CEO of the company always inspirit me to try again and again even though it was difficult. These hard works that were put into each project payed-off when noticing those students was full of energetic with their lab. All of them leaved the class with smiles! However it not finished, after each session that the students finished, they required to take the exam in order to graduated from Arrowdot. I was awe that some of them admitted their knowledge to me. The students seeked for supports whenever they perplex in any subjects. From this, students can master concepts at university which lead to a higher chance to be employed.

The internship was terminated, I realized that Cambodia has many change agents in technology. That internship made me gained confidence to help my country where that led me to have a Ted Talk about Cambodian Technology.

Ted Talk believes that ideas worth spreading. Yearly, International School of Phnom Penh (ISPP) hosted a Ted Talk event, and I been hunting to be one of the speakers since 2016. Finally, I got selected to be one of the speakers in 2017. I decided to give a speech that combated the old mineset that prevent those intelligent-engineers from being successful. It was a 12 minutes talk, it included example of engineering projects that are inspirational: mind control robots, sand management system, and international robotic competition. The speech has given to about more than 150 participants and has posted in the TEDx Youtube channel.

I believed that it was a number priority to change Cambodian perspective on the engineering field since words is sharper than knife–if that works it will bring many supports in engineering field. This reflects, if majority of the Cambodia keep in mind that our technology is not as high level as other country, than it is a setback that prevents Cambodian engineers to be developed. As mentioned, it is important to first change people’s perspectives while time move on technology will be better and better.

I understand changes does not have to happen from young generations, changes can happen by anyone regardless of their age, skin color, or gender. People always contribute positive changes to the country, they did not realized that they did it because change–to me–happened from one effort of doing it, not from what one think of doing it. The two examples above were the two that I always memorised. Throughout the whole year I might contributed greater than two. Everyone should have a fidelity inside them and they should begin the journey of small actions because “Idea don’t come fully formed. They only become clear as you work on them. You just have to get started” – Mark Zuckerberg

Here is my timeline in 2017-2018 (YEAR SIXTH)

Keith’s team project, trying to find your passion and set goals for the future.
My classmate at the Arrowdot lesson, the last day of the class! 🙁
Angkor Thom race
Cryptocurrency Presentation! Listen to two brothers who’s vision was to create a Serey Coin.
Cambodia Eyes Sight check!
Arrowdot Internship during the summer break. This guy is very passionate in technology even though he thinks he not good at it.
An experiment about ultrasonic sensor to measure the distance of objects.
Visited I thinkAsia, an animation company in Phnom Penh, to learn about animation.
The picture of myself, doing a Ted Talk about Cambodia Technology.
This is a project that some of our seniors hosted to collaborate with students outside of the school in order to talk about gender.
Our TosTov meeting about our future plan!
Mr. Hongly repaired the meat with butter on top of it!
This is what it ended up after Mr. Hongly prepared
Mr. Vuthy, Mr. Rithy, and Mr. Davith were running with me. It was very tired!


That was the time where all of the seniors had their bike ride and it was the time where the JourneyOfChange lunch their business!


The Tech4Good Event×321.png

During the past 3 weeks, Sreyneag and I got invited to participate in a collaborative event at the Asia Foundation. The event was about talking to other startups who play a major role in Phnom Penh. For the first time, I felt a bit shy and did not feel comfortable to do it since everyone in the event are high-level people. From time on, I began to talk to one person, then another and another and everyone would want to come and talk to me and Sreyneag. People would ask me a lot of questions related to Liger, and I tried my best to answer all of the questions. Most of the questions was, “how do you get to learn at Liger?” To be honest this question was a bit boring to me. When I answered it, they started to ask more into it and how can I remember all of it since it was 6 years ago! Indeed, I felt awesome to talk to different people and get to know their experiences. 

One important lesson that I learn about choosing the right person the work is to use the trust. Mr. Morokot was a tech person who owns a startup that now very successful said that: I higher people because I trust that person to do great things to the company and if he/she can not do it there is nothing I can do just to kick them out. That was a phenomenal lesson that I learn from Mr. Morokot! 

Vision-Setting and Professional Development

First of all, have you ever thought about your career? Do you have any concerns about it? Have you come across to a thinking that in the future you might won’t have a job or education? 

Personally, I came with these kinds of questions a bunch of time. I have a lot of worry about my future after graduating from Liger. I don’t really see my path clearly yet. I don’t really know what are my strength and my weaknesses yet, but I do know what my interests. I try to seek help with when these kinds of questions poke into my mind. So yesterday, I spent my two and half hours participate in a workshop from our senior students. I was a very great opportunity for me to spend those time in finding my career after Liger. In the workshop we sent most of the time answering the questions and discuss in a group of four. It was a bit difficult to me to share my goal with other people, but at the end of the workshop, I started to not shy of sharing. I did define my weakness and my strength, plus I created my plan in order for me to reach my goal. 

Continue reading “Vision-Setting and Professional Development”

Doppler Effects of Meteorology


“” source.

Doppler effects are used in many types of technology, and this is one example of using Doppler effects to work meteorology. The common design of the weather radar is a radar that covers with the sphere material around it (we can find this in Cambodia, it’s after the Chbar Ampov bridge there is a big ball and there is a radar inside there). The full word of radar is RAdio Detecting And Ranging. Doppler radar has a transmitter and a receiver. The transmitter transmits microwaves in 360 degrees into the atmosphere, and then the receiver is waiting to receive those signal that will return back. The signals that receive is called the radar echo. Precipitation is the one that reflects the microwaves back. The information that the receiver receives is in two form: relative and velocity. Relative tells where the precipitation is; the velocity, happens only in the Doppler radar, output the velocity of the wind. If the frequency is high the precipitation is moving toward the radar; if the frequency low the precipitation is moving away from the radar. Here is an example, “If particles switch from moving toward and then away from the Doppler radar over a small distance, the source may be a tornado.” As a result, Doppler effects benefits a lot to human, the concepts can save people’s life from storms like a tornado.