What do Young’s Modulus, Google spreadsheets, Borax, Elmer’s glue, and frog saliva have in common?
Daniella Duran’s advanced class in nanoscience for Valencia High School juniors and seniors.
Duran recently took an online professional development course in computational thinking for teachers.
Now she is employing her new skills to show her students how to “model” frog’s saliva using Elmer’s glue and Borax and then input this and related lab data onto Google spreadsheets they’ve pre-coded with an equation known as Young’s Modulus.
That is a mouthful, yes, but consider the hungry frog eyeing a succulent grasshopper for dinner.
The frog, with its sticky saliva and its long, elastic tongue, can snag large prey faster than you can blink an eye—in 70 milliseconds, to be precise.
In a sense, the saliva of these jumpy amphibians is a natural nanotechnology, which in this case is a non-Newtonian fluid, meaning it can act as both a solid and a liquid (more on this later).
Duran’s goal is to have her students develop their own nanotechnologies in small teams using computer thinking skills and related tools, such as how to use Google spreadsheets to analyze and model data. At the conclusion of the course, they present their findings in a competitive poster session.
So, who is Daniella Duran and why is computational thinking so important to her?
She is a bright, inquisitive and energetic high school educator who teaches an advanced class in nanoscience to juniors and seniors and chemistry to sophomores in Valencia, CA, just north of Los Angeles.
She is also the type of teacher that Rutgers University Professor Midge Cozzens and her colleagues are attracting to their professional-development course in computational thinking for secondary school teachers. The online course, entering its third year in 2021, is underwritten with a National Science Foundation Grant.
To date, 182 teachers from at least ten states have taken the course, which generally lasts four to eight weeks, with encouraging results. The course has provided classroom inspiration for educators that run the gamut— from librarians and third-grade teachers to English teachers and advanced-science teachers like Duran. Upon completing the course, teachers receive $1,000 and a professional-development certificate.
Duran, who discovered her love of teaching while pursuing an undergraduate degree at UCLA, obtained her masters degree and education credentials from Stanford University. Over the last 10 years, she has worked with UCLA to develop nanoscience curricula for other high school teachers.
“I have become the poster girl for nanoscience, at least on the West Coast,” she said.
Nanoscience is the study of science at an exceedingly small scale. A nanometer (nm) is one billionth of a meter, 0.000000001 or 10-9 meters. Human hair, for example, is approximately 80,000-100,000 nanometers wide.
A nanotechnology is one that solves real world problems at a nano scale. Duran says her students, in their nanotechnology projects, often gravitate towards solving problems like environmental protection and sustainability, no surprise given the wildfire devastation caused by climate change in southern California.
“It’s really engaging the kids, and it gets them excited,” she said about her class. “They see science as something for the future, not just the past.”
In teaching science, Duran must work continuously to improve her own knowledge and skills. She discovered the Rutgers University course in computational thinking while conducting an Internet search for new ideas and materials to do just this.
Although computational thinking as a concept is a product of the computer age, it is essentially a highly structured way of identifying and solving problems, and it is made up of four parts:
Decomposition – breaking down a complex problem or system into smaller, more manageable parts.
Pattern Recognition – looking for similarities among and within problems.
Abstraction – focusing on the important information only, ignoring irrelevant data in deciding how to solve the problem.
Algorithms – developing an equation, a step-by-step set of rules to follow in solving the problem.
“They have to decompose a problem, and then pullout key variables to find a solution,” Duran said of her students.
An especially useful tool Duran adopted from the computational thinking course is how to use the full power of Google spreadsheets by coding individual cells with equations that automatically analyze entered data. In the past, students had to compute data sets individually, one by one.
She also uses Google spreadsheets in her chemistry classes so students can develop graphs that more effectively “tell the story” of solutions to chemistry problems.
“I would not have been able to develop that activity without that (computational thinking) training,” Duran said.
At first, she was not sure how her students would take to the sophisticated use of Google spreadsheet, graphs and equations.
“I like to give them a challenge that takes them out of their comfort zone, but with structure,” she said. “I was actually really nervous, but they were great. They got to choose what way they thought was best to tell the story with a graph. They did it and they showed me their product.”
Let’s return to frog’s saliva, that non-Newtonian fluid mentioned earlier.
Due to the pandemic, Duran teaches her students virtually using her home computer, which normally would make it difficult to conduct lab experiments.
To skirt this problem, Duran had Elmer’s glue, Borax and lab instructions delivered to each of her student’s homes. The goal of the lab is to mix these ingredients with water, in varying amounts, in an attempt to mimic the properties of frog’s saliva.
Mixing Elmer’s glue and Borax with water produces a sticky and pliable substance akin to Silly Putty.
Depending on the mix, this slime can act like a solid (imagine a bouncy rubber ball) or a fluid (imagine molasses seeping on a warm day). As the lab progresses, students measure a number of variables, such as resistance and elasticity, data that is entered into their Google spreadsheets, along with related data collected in an earlier “penny” lab, for computation and analysis until they come up with an approximation of frog’s saliva. The formula in the spreadsheet that does the calculations, Young’s Modulus, is named after the 18th century physicist Thomas Young. It calculates the elastic properties of a solid undergoing tension.
The unique property of frog’s saliva is its ability to act as both a solid and a liquid. This gives it a huge advantage over its prey. When frogs first wrap the tips of their long elastic tongues around an insect, the saliva acts as a liquid, seeping into the insect’s legs, eyes, mouth and every possible opening. When the frog whips the tongue back into its mouth, the saliva hardens, making it difficult for the prey to escape.
The lab experiment enables students to practice using the tools they ultimately will need to develop their own nanotechnologies in finding solutions to real-world problems. It also shows them how data can be collected, analyzed and manipulated to solve problems—in much the same way that computers solve problems.
Generally speaking, high school students are more comfortable with “pictures” such as graphs that model solutions to chemistry or nanotechnologies, Duran said.
However, she wants to take them to the next level.
“I am encouraging students to think of equations and algorithms as models to describe cause and effect,” she said. “I told them computer programming is the future. Computer programs streamline data to find answers using logic and sequential thinking.”