In the chapter The Long Tail of the Law, in Alex Bellos’ book *The Grapes of Math*, he shows some different statistical patterns that share the same properties:

## Sum/product of consecutive numbers and other math shortcuts

If you have studied some of the old SAT questions at some point you may have gone through questions like –

4 consecutive numbers sum to 166. What is the product of the numbers? or…

3 consecutive even numbers sum to X. What is their product?

The way the tutors and the online tutorials show seems to always be to algebraically solve this – for example 4 consecutive numbers would solve x+x+1+x+2+x+3 = 166, collect terms and solve…

However there is another way that works for this and works for other similar problems.

Continue reading “Sum/product of consecutive numbers and other math shortcuts”## In search of the best scientific calculator for Librem Phone/Pinephone

While many apps do run on Librem 5 phone, there are many yet to be fully working on the small screen. In this post we explore the various calculator apps for Linux and see which might best work as a student/engineer’s go-to calculator:

Continue reading “In search of the best scientific calculator for Librem Phone/Pinephone”## Slide rule enters the 21st century

Some time ago I came across this online tool in a newsletter article – this is a very cool slide-rule-emulator that will not just let you move two slides, but actually slide it for you as you run an equivalent digital calculator calculation to the right!

If you haven’t ever used a slide rule before, it works on properties of logarithms, and the principle that log(a)+log(b) = log(a*b). Now it wouldn’t be very interesting to just have two normal rulers together, as sliding and adding would just let you do problems like 5+5 = 10 or 50+50 = 100 if you scale the numbers. With logarithmic scale, the spacings are off and it allows you to do multiplication in adding the numbers.

Continue reading “Slide rule enters the 21st century”## One more way to fight COVID-19… with your computer!

There’s a lot of computing power into finding a solution for COVID-19, and Digital Ocean just featured a new way to get involved – make your own droplet (virtual computer) to run distributed computations.

Continue reading “One more way to fight COVID-19… with your computer!”## Analyzing Scott Flansburg’s Nines Trick

There’s an old math trick that goes like so – choose any number… say 171…. add the digits and subtract.

171-9 = **162**

Take its sum of digits and subtract them…**162** – 9 = 153

Take its sum of digits and subtract them… Continue reading “Analyzing Scott Flansburg’s Nines Trick”

## The only metric guide you may need

Kilometers, Centimeters… microfarads, farads… They units are all a multiple of 10, but that doesn’t make them that much easier as you are first learning them. What is 1.09km in cm? or 1205cm in km? With a quick jotted down note card you can very quickly see what any commonly used metric unit converts to!

## Think outside the box for the most optimal recycling solution.

Today we did some up-cycling of political ad signs. After elections these generally go in the trash, but Talent Maker City had a public event to build some cool stuff out of these corrugated plastic boards! *(Update- see the howto for version 2 of a durable cargo bicycle box here)*

Continue reading “Think outside the box for the most optimal recycling solution.”