Is your octopus a boy or a girl? Here’s what you need to know to figure it out!

IsabellaY carefully examining the arms of one of two octopuses which we provided to our students for a cephalopod gender-determination exercise.

We’ve just finished our reading of The Octopus Scientists. Before diving into our next book, we gave our students a chance to put some of the information they’d gleaned from the final three chapters of Sy Montgomery‘s exceptional book to hands-on use. They were challenged to determine the gender of each of two octopuses by examining the creatures’ limbs. In the photo above, you can see Isabella Y. in the process of comparing the arms of one of the pair of cephalopods used in the exercise. The other octopus is shown below, in the hands of Charlie C.

CharlieC is checking out the other octopus's arms. His copy of 'The Octopus Scientists' is visible on his desktop, beneath his gloved hands.

A passage in Chapter 7 of the The Octopus Scientists describes the moment at which one of the biologists featured in the book was able to discern the gender of a grapefruit-sized octopus which she’d spotted searching for prey a short distance from its den: This is a female, because she has suckers all the way to the tip [of her third right arm].

Now you know the secret of telling a girl octopus from a boy octopus. Suckers run all the way down every arm of a female but a male has one arm (called the hectocotylus and usually its third right appendage) that is quite unlike the rest. Some distance from the tip, the suckers stop and that arm ends in something quite different.

Did you notice the strikingly beautiful, iridescent blue oval visible on the flank of the creature in the second image in this post? That’s an ocellus, or false eye. Each of the octopuses handled by our students had a pair of ocelli, one situated beneath each eye. Some scientists believe that the presence of ocelli, which were larger than these animals’ actual eyes, may help deter certain predators. Currently, howevever, the jury is still out regarding the purpose of cephalopod ocelli. Perhaps one of our students will go on to become an expert on marine invertebrates and get to the bottom of this mystery someday!

Finally, all of the animals used in this activity were purchased already deceased from a third-party vendor.

In this entry we wrote about CharlieC2016, Did you know?, Intermediate English Fun, IsabellaY2016, Scientists int he Field

Is the pasta a hollow tube? Using a dichotomous key to classify pieces of pasta.

KatieL using a dichotomous key to identify a piece of pasta during Saturday morning's quiz.

1. Is the pasta a hollow tube? If so, go to #2. If not, go to #4.
2. Is the pasta straight? If so, it’s penne rigate. If not, go to #3.

Those are the first two of a total of five questions comprising the dichotomous key which Katie L. is wielding in the photo above and, yes, the piece of uncooked pasta in her hand is indeed penne rigate, penne sporting ridges. Dichotomous keys are incredibly useful tools for classifying, well, just about anything. Best of all, they’re quite straightforward to use. One moves down through the dichotomous key, at each step choosing between two different, readily discernible physical characteristics of the specimen to be IDed. The first step in our pasta classification key asked students whether a given piece of pasta was tubular or non-tubular. Since penne are tubular, the next dichotomy was straight versus curved. Penne are straight.

We’ve been reading Sy Montgomery‘s The Octopus Scientists (a recent addition to the excellent Scientists in the Field series) with some of our students. The scientists featured in Montgomery’s book spend weeks on the Polynesian isle of Mo’orea, searching for octopus dens, collecting the remnants of the creatures’ meals (empty crab carapaces, scallop shells, and the like), and administering personality tests designed to characterize the octopuses’ psyches. A passage in Chapter 5 explains how a member of the team tasked with identifying the octopuses’ prey species goes about his work.

KatieL using a dichotomous key to identify a piece of pasta during Saturday morning's quiz.

The actual words dichotomous key don’t appear in the text, perhaps edited out due to concerns that loading the book down with terminology might blunt its appeal to some younger readers. Nevertheless, dichotomous keys are what Montgomery is describing on pages 36-37. Many of our students are aspiring scientists and engineers, so we wanted to ensure they’d be acquainted with the concept. First, we drew their attention to that portion of the book and introduced the term during our in-class read-and-discuss periods. That week’s reading comprehension homework assignment included a question intended to hone their understanding of this method of classifying things. Half of the reading comprehension section of last week’s quiz challenged them to actually use a dichotomous key — to classify pieces of pasta.

We drew inspiration from a similar exercise included by the Cornell Institute for Biology Teachers in their dichotomous key lab, but we wrote our keys from scratch, used a different mix of pasta types, and worked to make the activity fit the constraints of a quiz-taking situation. It turned out to be a heck of a lot of fun!

We have something even more special planned for the coming week’s quiz, which will cover the material in the final three chapters of The Octopus Scientists. As the saying goes, watch this space!

In this entry we wrote about Did you know?, Intermediate English Fun, KatieL2013, Scientists int he Field

Happy holidays! Blink and it’ll be 2017!

CalebC and AdrianW hefting their holiday gifts, which are highly relevant to the book they've been reading.

Happy holidays to you and your familys from us here at Accella! See you in 2017!

In this entry we wrote about Happy Holidays!

Can you control your teeth? Even in the presence of a strawberry Dip Dab?

CherylK sampling the forbidden delights of a strawberry Dip Dab!

Above, you can see one of our youngest and newest students, Cheryl savoring her first encounter with a strawberry Dip Dab.

Guess which book we're currently reading with some of our younger students?

Guess which laugh-out-loud funny book we’re currently reading with some of our younger students?

We’ll give you three hints:

  • The beguiling candy referred to in the story as a “dib-dab” corresponds to a real-world British sweet, the Dip Dab.
  • When we meet the protagonist, she is battling a microscopic foe whom she’s dubbed Germius Pavementius.
  • Nobody dies or is permanently injured, though a pet snake nearly meets a grisly end!

It’s a perennial favorite, perhaps surprisingly given the centrality of some kind-of-serious themes (the importance of self-control, moderation, and personal responsibility) to the story’s plot.

In this entry we wrote about CherylC2016, Daisy and the Trouble with Life, Kes Gray

Laserhand. Laserhand. Does the cool stuff a laser can!

LukeC is hot-gluing a piece of hookup wire onto his gadget glove.

Hello there! Here inside our workshop deep within Accella’s secret lair, we’re about to launch into further preparations for this week’s hands-on learning activity based on Nick and Tesla’s Super-Cyborg Gadget Glove, but we wanted to take a moment to share our enthusiasm for this book series with you. Here are some snapshots taken during one of our previous Nick-and-Tesla-inspired in-class making sessions.

The photo that kicks off this post shows LukeC wielding a Bosch hot-glue pen at his desk, attaching some solid-core 24-AWG tinned copper wire to the humble article of American-style workwear which he’s already begun transforming into his very own super-cyborg gadget glove!

AnnaT stripping the PVC insulation from a piece of wire that will be incorporated into her gadget glove.

In the image above, Anna is deftly using one type of automatic wire stripper to expose a length of tinned copper that a short while later, when brought into contact with another exposed bit of copper wire, allowed electricity from a CR2032 battery to flow through a 10mm white-light LED mounted on the tip of her gadget glove’s index finger.

The Nick and Tesla stories star an indomitable and highly resourceful duo, eleven-year-old twins who happen to be the latest generation in a family with a proud tradition of naming its children after famous scientists. They solve mysteries and foil baddies’ schemes using their wits and gadgets which they cobble together on the spot and at short notice from readily-available odds and ends.

The first step-by-step activity in this particular Nick and Tesla volume guides readers through the process of equipping a simple work glove with a LED signal light. Here’s Anna testing hers:

AnnaT testing the signaling LED feature of her gadget glove.

Here’s a closeup of Charlotte’s gadget glove in action:

CharlotteB using a different kind of automatic wire stripper to remove the insulating sheath from a length of wire destined for her own glove.

This week, our students will be equipping their gadget gloves with piezo buzzer alarms and, depending on how quickly we’re able to work, sound-recording modules and secret-message-revealing UV LEDs!

In this entry we wrote about AnnaT2012, CharlotteB2013, Intermediate English Fun, LukeC2012, Nick and Tesla's Super-Cyborg Gadget Glove

Can you spot the spelling error on this Pizza Hut coupon?

Can you spot the spelling error on this Pizza Hut coupon?

Can you spot the spelling mistake on the coupon shown above? The staggering wrongness of the misspelled word probably leapt out at you. If so, you may agree with the views expressed in the remainder of this post. If not, then you probably ought to read on anyway.

The marking scheme that we employ while grading our students’ reading comprehension homework assignments has evolved over the years, but the penalty for a spelling or capitalization error has remained the same from nearly the start: five points deducted each time, from a possible twenty points per answer. A few such mistakes can easily sink a factually-correct answer. At first blush, to some of you out there, this may seem a bit harsh. We would beg to differ.

Misspelling a word is one of the easiest-to-avoid writing blunders. This is particularly true when it’s a case of two letters having been transposed (e.g. writing “cta” where “cat” was intended). Capitalizating a letter that ought to be lower case, or vice versa, is in the same ballpark. Even if one of these boo-boos slips into a sentence, it can be caught and corrected very easily. All that’s required is a critical eye and the willingness to spend a few moments exercising it.

Imagine that it were possible to sit down and write out a bullet-point list of essential mental tools, the cognitive skills which every young human needs to acquire on the path towards a successful and rewarding adulthood in today’s ultra-globalized, hypercompetitive world. If we had such a list, the natural thing to do would be to replace the bullet points with numbers. We’d rank the skills according to two criteria: the relative ease with which a skill can be developed and the potential payoff for those who practice it. Proofreading would surely be nestled somewhere near the top of the prioritized list of skills — which is why we knock off a quarter of a homework answer’s score for each spelling or capitalization mistake.

Have you read this far hoping we’d tell you which word the Pizza Hut coupon designer(s) misspelled? We will, but before we blurt out the answer wouldn’t you rather have a hint and a second chance at identifying the error? Here’s your clue: the word in question appears twice on the face of the coupon, once spelled correctly. Have you found it? If so, give yourself a well-deserved pat on the back. Make that a double-pat if you saw it instantly, at first glance.

Still stumped? We direct your attention to the box below. Hover over it with your mouse or other pointer and Pizza Hut’s mistake will be revealed.

TAKWAWAY should have been TAKEAWAY!

In this entry we wrote about Highly visible English errors around town

Non-Euclidean geometry experiment: Please do try this at home!

SoniaC, wielding her protractor, measuring the angles inside the triangle on her table tennis ball.

Looking for an intellectually meaty graphic novel that blends historical, technological, and mathematical elements into a quirky steampunk masterpiece? Have a hankering for intensively footnoted fiction? You’re in luck! We recently wrapped up our reading of Sydney Padua’s The Thrilling Adventures of Lovelace and Babbage: The (Mostly) True Story of the First Computer and can confidently and enthusiastically recommend it to, well, nearly everybody. Yes, it truly is that good.

After wringing readers’ hearts with the true tale of the unfulfilled promise of Ada Lovelace and Charles Babbage‘s Victorian-era mechanical computing collaboration, Padua spins a series of delightful counterfactual yarns set in a “pocket universe” in which Babbage’s mechanical computer is constructed and he and Lovelace become something like joint-CTOs of the United Kingdom. Padua has written many prominent nineteenth-century authors, engineers, and mathematicians into these stories as guest stars and she works aspects of their real-world accomplishments into the narrative in ways that ensure curious readers will pore over her magnificently crafted footnotes and endnotes and then, to learn more, head off to Wikipedia and Google.

Answers to the elliptical-space triangle quiz question in one section of our Upper Intermediate I classes.

The Thrilling Adventures of Lovelace and Babbage‘s final two stories are a short vignette featuring George Boole and introducing Boolean logic and a longer riff on the Alice novels of Lewis Carroll (aka Oxford mathematician Charles Dodgson). In the latter, Padua introduces non-Euclidean geometry. That’s why the reading comprehension portion of the quiz administered to our Upper Intermediate I students last weekend challenged them to correctly use Boolean logic’s three operators (AND, OR, and NOT) and also to measure the magnitudes of the three angles inside a triangle drawn in a non-Euclidean space. That’s what Sonia is doing in the image atop this post. Her and her classmates’ solutions are shown above. All of their answers were correct, within a small margin of error to allow for the difficulty inherent in using a semirigid plastic protractor to measure angles on a fiddly little ping-pong ball.

RyanY carefully aligning his protractor with one of the vertices of his non-Euclidean triangle.

A sphere’s outer surface is a commonly-used model in explanations of elliptical geometry and, as you’ve likely guessed if you’ve scrutinized the images included in this post (like this closeup of Ryan aligning his protractor with one of the vertices of his elliptical-space triangle), the non-Euclidean space which we utilized for the quiz happened to be the oh-so-prosaic exterior of a table tennis ball. We prepared enough balls, each bearing a differently-proportioned triangle, to ensure that every student in each class would be measuring a unique set of angles.

HarrisY measuring his elliptical-space triangle's interior angles.

Drawing a triangle and summing its interior angles is one, but not the only, way to discover whether one is dealing with Euclidean or a non-Euclidean geometry. In familiar flat-plane (i.e. Euclidean) geometry, the magnitudes of the interior angles of any triangle always add up to exactly 180°. The angles in a triangle drawn in a non-Euclidean space add up to either less than 180° (in hyperbolic space) or more than 180° (in elliptical space). This was borne out by the results of our in-class experiment-disguised-as-a-quiz-question. In the answers to this question shown above, the sums of the triangles’ angles ranged from 245° to 365°.

We had read and discussed the relevant The Thrilling Adventures of Lovelace and Babbage endnote in class but, as indicated by the hand-crafted graphite shocked-face emoji that graced one quiz paper, nothing beats hands-on experience!

In this entry we wrote about HarrisY2010, RyanY2012, SoniaC2010, Sydney Padua, Upper Intermediate English Fun

They’re not like other wasps…

We're reading Kenneth Oppel's chills-and-thrills-packed middle grade novel 'The Nest'.

Kenneth Oppel’s The Nest is a rare sort of book indeed — a children’s psychological horror novel that manages to build and sustain suspense for its target audience and for adult readers alike. The gorgeous and innovative jacket design and masterful illustrations by award-winning illustrator Jon Klassen are the icing on the cake of Oppel’s magnificently well-told tale.

As the college zoology major employed as his and his sister’s babysitter explains to Steven, the story’s protagonist, the wasps that have constructed a nest beneath the eaves of his family’s home are rather different from regular wasps. Steve’s was already deathly afraid of wasps but, not too many pages into The Nest, he discovers the hard way that he’s allergic to their stings. He’ll need to keep an EpiPen close at hand until he completes a regime of desensitization injections, assuming his parents ever get around to scheduling the shots at all. Meanwhile, that nest (which likely resembles the first nest shown in The American Museum of Natural History’s 6 Exquisite Structures Built By Wasps listicle) is getting larger with each passing day.

Steven has been plagued by overpowering feelings of anxiety and loneliness throughout his young life, so the possibility of dying from a wasp sting would probably be just one more thing for him to worry about if his longstanding psychological and emotional issues hadn’t been exacerbated by the recent birth of his sickly infant brother, Theodore. With the baby in and out of the local hospital on practically a daily basis, Steve’s mom and dad are running on empty, both physically and emotionally, much of the time and aren’t able to step up and provide their eldest child with the support and attention that he so clearly wants and needs. His younger sister, the family’s middle child now, is happy and content — perhaps because she’s oblivious to Steve’s travails and the health challenges facing the newest addition to their family.

It’s here that, as if in answer to his sort-of prayers, an otherworldly and seemingly omniscient being shows up in Steven’s dreams to assure him that she has the know-how and the wherewithal required to fix up baby Theo and is, in fact, already on the job. Everything is going to be OK! What a relief! Of course there’s a catch. Isn’t there always?

The kids in our Intermediate-level classes have had a week to read, re-read, and mull over the events of the first fifth of The Nest. Oppel does a great job of weaving the characters’ details and other background information into the meat of the story so even this first chunk of the book moves along quite rapidly. Needless to say, we’re really looking forward to getting our students’ reactions to what they’ve read. We’ll also be distributing wasp specimens preserved in acrylic, like those shown flanking our instructor copy of the novel in the photo atop this post. It’s going to be a blast!

In this entry we wrote about Intermediate English Fun, The Nest

Newton’s Law of Gravity is an Inverse-Square Law!

We're reading Carolyn DeCristofano's A Black Hole Is NOT a Hole.

Two weeks ago, students in some of our classes began reading the latest and greatest elementary-school-level introduction to the astrophysical objects popularly known as black holes: Carolyn DeCristofano’s wonderful A Black Hole Is NOT a Hole, a book that has managed a seemingly impossible feat: delighting clued-up reviewers like physicist and children’s space science author Marianne Dyson and garnering praise from readers (see, for example, ABHINaH‘s 3.88 score on Goodreads).

Early in the book, DeCristofano explains that the force of gravity between two objects is greater when the masses of one or both are greater and/or when they are closer together. That’s true, but we want our students to have a bit of a better handle on Newtonian gravity so we went a step further and introduced the equation for Newton’s law of universal gravitation, a prime example of what is known in science as an inverse-square law.

In his answer to this quiz question, Ryan H. shows that he grasps the implications of gravity being described by an inverse-square law!
We enjoyed walking our classes through the effects, in terms of the “pull” of gravity, of dialing the masses of two objects up and down and changing the distance between their centers of mass. Since it can be described by an equation in which the value for distance lives in the denominator and is squared, halving the distance separating two things causes the force of gravity to increase fourfold. Likewise, doubling the distance between two things diminishes their mutual attraction to a quarter of its former strength.

We included a question in the next lesson’s quiz that challenged our students to demonstrate a qualitative understanding of Newtonian gravity. Some quiz-takers aced it (see the question and Ryan H.’s answer above) but others were stumped, so we’ve put together some additional exercises and will be revisiting the topic.

In this entry we wrote about A Black Hole Is NOT a Hole, Carolyn DeCristofano, Did you know?, RyanH2014

All aboard the STEAM train!

Quincy L. explains how the example set by Mary Somerville encouraged Ada Byron Lovelace to pursue her passion for mathematics.

At Accella, with some of our younger students, we recently read Ada Byron Lovelace and the Thinking Machine. Laurie Wallmark‘s book, lavishly illustrated by April Chu, is more than just a wonderful biography of the nineteenth-century woman now acknowledged as the first computer programmer. It’s a carefully and lovingly crafted STEAM (Science, Technology, Engineering, Arts, and Mathematics) recruitment tool targeted at children ages 5-8.

Why was a scientist and mathematician named Mary Fairfax Somerville an important role model for Ada? Quincy L.’s answer to this reading comprehension homework question (see the image above) was flawless but we’re happy to report that each of her classmates also hit the proverbial nail on its proverbial head.

At Accella, we’re unabashed STEAM maniacs and we prepare our reading comprehension materials completely in house. That’s how we’re able to fill our curriculum with books like Wallmark’s ode to Ada Lovelace or the hands-on look at the inner workings of automobiles (How Cars Work: The Interactive Guide to Mechanisms that Make a Car Move) that we’re wrapping up now with classes of slightly older children or the introduction to gravity and astrophysics via black holes (A Black Hole Is NOT a Hole) that we’ve just begun exploring with some of our other students.

In this entry we wrote about Ada Byyron Lovelace and the Thinking Machine, QuincyL2015