Number Sense Tricks // Video Tutorials

Well I know I’ve been talking about it for a while (and at one point settled on not doing them), but I finally decided to do something about providing video tutorials that are meant to accompany the material supplied by my Number Sense Manual. Here is a quick sample video (it was literally a single-take unrehearsed screen capture — the “real-deal” instructional videos will go a lot more smoothly):

My current screen capture set-up is:

If you have any suggestions on how to better screen capture, please leave a comment on this post (note: it will need to be Mac-compatible).

I plan on having the video broken up into two parts: instruction and examples — with a minimal amount of my handwriting as possible. The videos are planned to be less than 5 minutes long each and will follow, sequentially, with the sections in my Number Sense Manual. Eventually when I revise my manual again, at each section I will provide a hyperlink to its corresponding youtube video that will further aid in the trick’s explanation.

I hope to do two to three tricks a week. Also, if you e-mail me with a question on how to do a problem, I’ll either give you .pdf containing the step-by-step instructions or a brief video. So there you go!

Effective Altruism

As readers of the website might know, I am an avid enthusiast and follower of the FI/RE movement (e.g., Financial Independence, Retire Early). If you want to read more about that, I suggest starting with this article here and follow it up with more of my favorites here.

There has been a complimentary theory that has started to revolutionize charitable giving that many FI/RE proponents have endorsed that is called Effective Altruism. The gist of Effective Altruism is that if you truly believe all lives are equal then you should focus your giving towards having the most impact with regards to saving lives. Oftentimes, this means donating towards health-related organizations that operate in under-developed countries as each donated dollar tends to go farther in those places.

The person most associated with the movement is popular philosopher Peter Singer. He’s written several books about the subject and put on a pretty convincing TED talk which you can watch below:


Singer has also set-up a website at that encourages people to pledge towards Effective Altruism and highlights charities that tend to provide the most benefit for the donated dollar. My wife and I chose to donate our funds towards the Fistula Foundation, but you can take a look at other suggested charities here.

If you have the means, I highly encourage doing your own research about effective altruism (that includes reading-up on some of the nay-sayers as well) and come to your own conclusions on how and where to give.