Lux Digital Count Up/Down Timer

I’m a teacher in a school that uses a lot of timers. And it’s not just for exams – a well-paced lesson sometimes depends on hitting certain timestamps, and nothing can keep you accountable in quite the same way as the humble timer. The simple act of counting down is a surprisingly versatile arrow in the quiver of teaching practices.

At school, we need our timers to do just a few things but to do them well. The LUX CU100 scores high marks in all the necessary categories and gets extra credit for its ability to take abuse.

First, the digital display is large and extremely easy to see. Not only is this essential for quick glances from across the room, but it is easily read by students when I pop the device under a document camera set up to a projector. For timed writing and drills, the clear display helps kids self-evaluate their pacing and keeps them accountable. Being able to set the timer in second intervals – which are also given equal prominence in the display – is likewise a must in the classroom.

The ease of use is fantastic. Simple, chunky buttons – look at it once and you know how to use it. The timer has a good hand-feel, too, and the buttons chirp pleasantly and reassuringly when pressed. I seem to be allergic to correctly operating the stopwatch and timer function on most wristwatches – give me yours and I can accidentally find out how many laps it will store but for the life of me won’t be able to reset the damn thing back to that comforting row of zeroes – so it comes as a pleasant surprise in the middle of class to reach for the Lux CU100 and have it do exactly what I want, every time. Hit the start/stop button and it begins counting up; hit the button again and it stops. To count down, click the minute or second buttons until the desired time appears in the display and click start to begin the countdown. Hold the minute and second buttons together to reset to zero. That’s it. Even very small children have no trouble operating it without instruction – useful when a child needs a five minute break to cool down in the hallway and you can send them with a timer so they know when to come back in.

There are a few other things that commend its use for teachers. The thing is a workhorse: a single AAA battery powers the timer and I haven’t needed to replace mine in three years of daily use. And it just shrugs off abuse. I’ve literally kicked it across the room, stepped on it, and, on a weekly basis, dropped it half a dozen times from standing height. Aside from the battery cover popping off occasionally (without a loss of function and easily snapped back into place), the timer appears like new.

It also comes with a clip, magnet, and easel on the back. I don’t use any of these except the magnet, which exerts a significant amount of force. (In fact, I sometimes have a second or two of unexpected trouble pulling it off of the projector stand when it is laid flat on top.)

The alarm is loud enough to be heard over a room of chattering students, which, really, is all that I ask from my timers as a teacher.

A few caveats. I’ve noticed the display is sensitive to direct exposure to heat, darkening into unreadability if placed beneath a heat source for extended periods. (This crops up when I allow the timer to be blasted by the heat exhaust from my projector.) While it’s a minor concern for the teacher, it may be something to consider if you are using this in your kitchen.

Of bigger issue is that every button beeps when pressed. I personally don’t find this annoying but I can see why someone would. Need 60 minutes? Be prepared to hear 60 beeps.

If something is going to break on the timer, it will probably be the little metal bar that flips down to form the easel. I’ve noticed the tendency for this piece to snap out of its holder at times, usually because students fiddled with it too much. As I almost never use the easel, this has never been an issue.

Having used a variety of timers, both in the classroom and in the kitchen, I have to say the little bit of extra cash for the Lux CU100 is worth it. It’s not the cheapest but it is the most reliable, most durable, and easiest to use of the bunch. Teachers who know know: if the Lux CU100 were a student, she’d be the top of her class.

-- Joshua John Mackin  

Lux Digital Count Up/Down Timer

Available from Amazon

Google URL Shortening Service

Google has a convenient URL-shortener service. Here’s how it works:

1. Select and copy your long URL into your clipboard.

2. Go to

3. Paste your URL into the box where the cursor is positioned.

4. Click the Shorten URL button.

5. Copy (Ctrl + C) the already “selected” short URL to your clipboard. (It looks like this:

Google keeps all your long/short URL pairs on display on that page for you to re-use in the future. (It’s public, but you can hide any pair you want.)

-- Roger Knights

WP 34S Scientific Calculator

This scientific calculator is very cool for two main reasons. First, it is a new open-source project driven by a small team of people who clearly love HP (Hewlett-Packard) scientific calculators. Probably no one at your workplace or school has this.

Second, in my opinion it’s the best option for anyone who ever fell in love with an RPN (reverse polish notation) HP calculator in the latter 20th century (e.g., HP32, HP42). That’s mostly because it is a reprogrammed version of an HP30b, so the key-feel is good and it’s powered by a fast ARM processor.

The latest similar offering from HP is the HP35s, which is too bulky and has known mathematical errors, poor design and quirky behavior. The WP34s solves these problems beautifully. The user manual is very well-written, but I recommend the fantastic WP34s Beginners Guide (also free).

-- Paul Bridges  

HUB-ee Wheels

Creative Robotics’ HUB-ee wheels are just what they sound like: hub wheels, where the motor is contained inside the wheel’s hub to save space on your robot. Hub wheels are great for complicated builds like rack-and-pinion steering rigs where you want wheels that both drive the robot as well as turn to steer. They also make for very clean builds because a lot of components you could normally see are hidden.

Each HUB-ee Wheel consists of a 12mm gearmotor, a small circuit board equipped with a motor driver chip and a quadrature encoder, as well a gearbox, all concealed inside the hub. They come in a small number of configurations: 180-1 and 120-1 gear ratios, available in either metric or imperial.

The wheels connect to a microcontroller with a Micro-MaTch ribbon cable, and Creative Robotics also offer breakout boards for managing these connectors, as well as a HUB-ee friendly prototyping shield. If you don’t want to use the breakout boards, Creative Robotics shows you how to cut a Micro-MaTch cable in half and attach the wires individually to the controller.

The HUB-ee wheels attach to your robot’s chassis one of two ways. The first are fairly typical M3 screws. The other is much more intriguing: the M3 holes also double as Lego cross-axle holes that accommodate a standard cross-connector pin. These holes don’t go all the way through, limiting the tensile strength of this attachment method. However, the cross-holes are on both sides of the wheels, allowing you add support to either side.

-- John Baichtal  

HUB-ee wheel

uFactory uArm

uFactory is a new startup in Shenzhen that makes electronic gadgets, most of which are sold through Kickstarter campaigns and then get featured in uFactory’s online store. A case in point for the success of the company’s business model is the Arduino-controlled uArm, a desktop robotic arm that can be operated via Bluetooth or a Windows computer.

The arm got its start with a successful Kickstarter that earned them a quarter-million dollars. Funders paid $185 (versus a future price tag of $255) for a complete kit, available in laser-cut acrylic or wood. It comes with 1 mini and 3 standard-sized servos. You’ll also get an Arduino clone as well as a shield for controlling the arm. The kit even comes with white cotton gloves (a tradition someone totally needs to implement in the States).

The business end of the arm is a type I’ve never encountered in a robot arm — it comes with a pneumatic vacuum gripper that picks things up by placing the applicator against a hard, smooth object and then grabbing onto it with air pressure.

The uArm a great challenge kit if you’ve graduated past the blinking Christmas tree kit and want something that’s really cool.

-- John Baichtal  

uFactory uArm

Khan Academy

Is there anyone who doesn’t know about Khan Academy, the free online school? A favorite of the digiterati, this website was founded by Sal Khan who started out by making video tutorials on how to learn algebra. He captured his instructional doodles on a black screen (rather than focus on his talking face) and these short intense classes were amazingly effective. Our son used them for high-school math summer school. Students love them because they can go their own pace, and back up when needed. Sal Khan branched out to cover almost every other school topic, from history to economics, in over 4,000 videos. I’ve searched for, and attended, specific lessons in his Chemistry set in order to brush up on a forgotten point. While his math and SAT prep ones are still the best, all his courses are free, and he still teaches better than the average teacher.

Overview of An overview of the different ways to use Khan Academy

-- KK  

SuperMemo + Anki

In high school, I tried to learn Spanish, and failed. In college, I tried again, and failed again. Then, in my thirties, I discovered SuperMemo, and within a year I had memorized thousands of Spanish words and phrases and was finally on my way to speaking Spanish.

SuperMemo is software premised on the idea that there is an ideal time to practice any item you are trying to remember. You want to practice when you have almost forgotten it. Too soon, and you waste your time, and even interfere with long term memory formation. Too late, and you’ve lost the trace, and have struggle to learn it again. There is a simple equation that describes the shape of the forgetting curve, but the exact curve is different for every item and for every person. There is no single “best pace” for memorizing all things.

However, your ideal time to practice can be predicted from your history of attempted recall. The inventor and memory expert Piotr Wozniak reduced this practice to software many years ago, and his technique, called “spaced repetition,” is now available in quite a few learning products, including Wozniak’s own SuperMemo, and an open source version called Anki. None of them are perfect from a usability point of view. But any of them will work far, far better than random study of flashcards. These tools will not give you all the pieces of the learning puzzle, obviously. Memorization is only one step. But it is a crucial, difficult, first step, and it is wonderful to get a boost.

I recommend SuperMemo or Anki to every student who needs to memorize: vocabulary, science and medical terms, names and faces, musical chords, technical specs — anything that can be reduced to a flash card.

SuperMemo for Windows (its main version) has a famously slow-to-evolve interface that will irritate anybody used to the convenience of modern UX, but it contains many wonderful features, including “incremental reading,” which is a way to save and remember passages from books and articles. Anki is quite primitive in terms of features, but has an up-to-date interface and is available on most platforms, including an iOS and free Android app.


-- Gary Wolf  

SuperMemo (Windows)

Free, donations welcome

SuperMemo iPhone app
Free, with in-app purchases for language courses

Science Fair Handbook

Science fairs are the hidden secret sauce for America’s innovation. They instill the joys of the scientific method early in impressionable minds. Sadly, science fairs are in decline in the US (and on the rise in China, which has a million kids do them each year.) Get your school to run one, or do your own.

My kids’ school promoted science fair participation, and one of our daughter’s projects made it to the California state level one year. In assisting my kids (yes it is okay) I’ve accumulated a entire bookshelf of science fair guides and idea books. The best of all these is the second edition of a 120-page book co-authored by the great science and science-fiction author Isaac Asimov. Aimed at parents wanting to help, and teachers hoping to set one up, it emphasizes the process of science fairing at the elementary school level. Basically, how to do a small experiment and report on it. Then how to judge it.

Unlike most science fair books at this level it is not packed with experiments recycled from others; the ideal experiment is one you don’t know the answer to. That makes your experiment more valuable and more fun for everyone. This handbook does list a few suggested topics by age to spur an idea. For inspiration of possibilities, we haven’t found anything better than old episodes of Mythbusters. As Adam Savage said in one, “Remember kids, the only difference between screwing around and science is writing it down.”

-- KK  

Science Fair Handbook
Anthony Fredericks, Isaac Asimov
2001, 128 pages

Available from Amazon

Sample Excerpts:



Developing a Hypothesis

After students have designed an appropriate question, they must turn that question into a hypothesis. A hypothesis is an educated guess, a statement of how the scientist thinks the experiment will turn out. It is a prediction, based on the best available information, of what the scientist believes will happen at the conclusion of the experiment. Although the hypothesis is founded on factual data the student has collected during the research stage, it is the student’s opinion deduced from those facts. A well-constructed hypothesis identifies the subjects of the experiment (plants, mice) and states what is being measured (rate of growth, weight), the conditions of the experiment (different-colored light sources, junk food versus regular food), and the results expected (light colors produce faster growth rates than dark colors; a nutritious diet produces higher weights than a junk food diet). Thus a student’s question about a specific area of interest can be developed into a hypothesis that forms the foundation of the student’s investigation.


Avoid clutter

It is important to include enough items to illustrate important concepts of the project, but it is equally important to avoid crowding the display table. Too many items detract from the display just as much as too few.


Scientific Thought

Is the experiment designed to answer a question?
Are the procedures appropriate to the area of investigation?
Is the topic or problem stated clearly and completely?
Has scientific literature been cited?
Have scientists or other experts been consulted?
Has a systematic plan of action been stated?
Is there a need for further research or investigation?
Is there an adequate conclusion?
Is a project notebook provided with the display?
Is the project notebook sufficiently detailed in relation to the scope of the project?
Have any problems or limitations that occurred been noted?
Is the amount of data commensurate with the scope of the project?
Does the student understand all the facts and/or theories?

Alphablocks videos

Up until about a week ago my 3 year-old had learned to recognize the 4-5 letters that are the initials for our families names (d for daddy, m for mummy) and was looking like he was ready to branch out beyond that.

Somewhere I heard about a BBC CBeebies show call Alphablocks, and got hold of the first series for him to watch. He loved it, especially the music of it, and the characters (his favorite is X, the superhero.) He’d ask for it a couple of times a day, and would happily sit through all 26 3-min episodes in one go.

Now, a week or so later, he knows almost all the letters of the alphabet, with their basic sounds.

It’s not a substitute for one-on-one time with a parent, but I can already see he enjoys books more now that he gets the meaning of the symbols.

With his older brother we used a book Teach Your Child to Read in 100 Easy Lessons by Siegfried Engelman, which I also recommend. But it was hard work for him, whereas Alphablocks has just been a fun tv show that he enjoys watching.

All the alphablocks episodes are on youtube (and BBC website – not sure about outside the UK), and dvd, and they look to be branching out to books, web games, and tablet apps.

If your kids have already made the connection of what letters mean, I’d recommend watching a couple of episodes yourself, and then watching them with your child.

-- Fraser Redmond  

Free on YouTube

HP 35s Scientific Calculator

The HP 35s is one of the greatest calculators of all time. Ok, I’ll revise that statement slightly: it’s the best calculator I’ve ever used. The RPN system is incredibly intuitive and useful, besides being much more effective and efficient than the traditional algebraic system. The buttons feel great under your fingers, both texture and response. It has basically every function I’ve ever needed (in engineering undergrad), and despite having a two-line display, its far preferable to my TI 83, because it’s much smaller than the TI, and of sturdier build. I went to the 35s, never looking back.

-- Leandro Rodriguez  

[I wouldn't say Reverse Polish notation (RPN) is intuitive, but its easy to get the hang of. -- Mark]

HP 35s Scientific Calculator

Available from Amazon