Monthly Archives: July 2023

Calculus for Mature Students

Math Meme from Math Lady Hazel

Like math, calculus needn’t sulk (to any degree)! In the hands of an excited middle-school or high-school math teacher, or with access to some creatively written (or online free) resources, the ABCs of calculus can even be taught to elementary school kids.

Think of Mr. Jaime Escalante who had successfully taught calculus to cohorts of Mexican-American students. There is zero excuse why we can’t emulate him to teaching it to financially disadvantaged or minority groups.

What’s Calculus to You?

Do you parrot the textbook definition of calculus to your students? The mathematics of (instantaneous) change. Or do you share it as the branch of mathematics that measures “how far an object has been going fast,” and “how fast an object has gone far”?

Moons ago, I cheekily approached or indirectly defined calculus via the division of zero as follows:

0 ÷ 0: The Raison d’être of Calculus

With some dose of irreverence, the bête noire of high-school or college math could turn out to be a much beloved topic even among the so-called innumerates or mathematically challenged.

Calculus for the Numerati

It’s debatably said that without an exposure of some delta-epsilon calculus, no man or woman can honestly claim to be “mathematically educated” or “mathematically civilized.” Sounds like mathematical pride or arrogance, isn’t it?

Or just an example of “mathematical elitism” à la Trump for those fakes who declare themselves as being a “very stable genius.” Even Einstein had remarked that calculus was “the greatest advance in thought that a single individual was ever privileged to make.”

Fr: Ryan Truong on Facebook’s “Mathematical Mathematics Memes”

Recently, while working on the Urban Calculus manuscript, I forced myself to reread some of the out-of-print pop calculus titles like David Berlinski’s A Tour of the Calculus, Steven Strogatz’s The Calculus of Friendship, and Mary Stopes-Roe’s Mathematics with Love to get an intuitive feel of the subject again.

For a long time, the thought of taking up the challenge to read Newton’s The Principia (even its annotated version) frightens me, because the complexity of the content is beyond me. I’ve a good excuse not to borrow the thick copy from the university library unless I want to look like a “mathematical snob” carrying it around, or use it as a temporary doorstop.

When Comics and Calculus Converge

Calculus for All

Let’s play our part in sharing the mathematical gospel of Newton and Leibniz that calculus needn’t be a four-letter word—how these two mathematical greats had exorcized the demon out of the division of zero.

Why not strive to be the “James Escalante” of your school, state, or country? You’d be the changemaker or mathematical savior in motivating some undecided or mature students to read a calculus course or module in college?

Differentially and integrally yours

© Yan Kow Cheong, July 30, 2023.

The Mask of Math

Mask Art as Therapy. Original un-memed photo from Hunny & Lummy’s “Masks of Singapore” (2021).

What mathematical or nonmathematical crisis are you presently facing or undergoing? Mid-life crisis? Existential crisis? Financial crisis? Relational crisis? Post-pandemic crisis?

Have you forgotten what it means to enjoy math? If you’re a school teacher or university lecturer, are you planning to leave the [Singapore’s or US’s or XYZ’s ] rigid educational system to pursue your mathematical dream?

If you’re an editor, are you longing for the day when you don’t have to handle those quasi-uneditable manuscripts once you’ve paid up your mortgage or send your children to college?

And if you’re a writer, do you long (or pray?) for those pseudo-math editors to get promoted to their next level of incompetency, where they’re less likely to adulterate your manuscript?

Math & Mask

Beyond the mask that we wear to function in our daily lives as math educators (lecturers, teachers, tutors, editors, writers, consultants, managing editors, publishing managers, …), who are we?

Do you see yourself enjoying the mathematical journey while you’re building your career or struggling to pay the bill? When you take off your daily masks, when you don’t feel the pressure to pretend, when you’d simply be yourself, what does it feel like? What does it smell like? What does it taste like? What does it sound like?

A Commandment to Deal with the Mask of Pride

Mathematical Synesthesia

Can you visualize the color of infinity? Taste the number zero? Smell the fragrance of pi? Or you think these synesthetic experiences are only reserved for autistics or idiot savants?

We all came into this world with zero, and we’ll also leave it with zero but the [mathematical] spirit of life we’ve lived in our lifetime. Are you always waiting for permission to write that math book? Or hoping that when you retire, you’d have the time (and space) to explore and pursue that math pet project?

Are you petrified that others might witness that you’ve been a victim of the imposter syndrome, as you get promoted and being tagged with bigger flowery job titles? Still struggling to fake it until you make it?

Unmask Your Math

To make a mark in math or math education in the local, regional, or international community, you need to strip your mask away. People want to see and work with vulnerable or fallible folks, who’re prepared to make a fool of themselves, to be a laughable stock or mathematical clown, and not to take themselves seriously.

What are you waiting for? Not some other time when you’ve accumulated enough zeros in your bank account, or next semester (or pandemic?), but today. Because when you’re financially free, you’re unlikely to have the energy to do that math thing you so desire.

Don’t die with a book inside you! Or miss tithing one or two years of your life to volunteer as a math teacher in some low-GDP countries to help raise the numeracy level of the locals. Or fail to resurrect that off-atrophied “math & art” project for a solo exhibition. It’s better to fail or experience the journey than regret on your deathbed.

Remember: Let not pride, insecurity, or failure prevent you from fulfilling your God-given purpose on this side of eternity, as you embark on your mathematical journey.

You needn’t do it alone: Seek Him and His wisdom for your mathematical needs and wants. Be fearless and free.

Fearlessly & faithfully yours

© Yan Kow Cheong, July 23, 2023.

A Question on Inequality

Fr: Ralph McConahy on Facebook

Many years ago, I read about the co-authors of a handbook for mathematics teachers in primary schools warning readers not to use the sign “<” or “>” (because the symbols were removed from the primary school syllabus); instead, they suggested using phrases like “more than” and “less than.”

For example, teachers were to avoid setting questions in these formats:

34 is 6 >
8 > 43 is

Instead, they’d rephrase them as “34 is 6 more than ☐.” and “8 more than 43 is ☐.”

Similarly, they’d refrain from posing inequalities questions such as the following:

7 < is 15.
9 < 25 is
.

And also avoid problem sums like the one below:

What is the largest (or greatest) whole number that can be placed in the box to make the statement true? 8 + < 40

Why the Ban (with or without a Fine)?

Based on teachers’ feedback that young (or even older) schoolchildren are often confused about the similarity of the two symbols < and >, that’s likely a key why that prompted local curriculum math specialists in the “fine” city to ban these “unequal symbols” in primary school mathematics moons ago.

Inequality Metaphors from the Sunshine State

Over the years, to reduce the confusion between < and >, some elementary math authors have come up with some witty ways to help schoolchildren remember which is which.

For instance, students are often taught to see the symbols as hungry alligators or crocodiles with gaping mouths—these reptiles always want to eat the larger numbers, so the open mouth will always face this.

Observe that the < looks somewhat like a lopsided L, which reminds us that it denotes less than. Or, in any true statement, the large open mouth of the symbol is on the side of the greater quantity, and the small point is on the side of the lesser quantity.

No More Ban

Like last year’s repeal of Section 377A in pseudo-puritan Singapore, based on the CPDD’s Primary Mathematics Textbook 2A (2022), the inequality signs too are now free to roam the pages of any MOE-approved primary 2–6 textbooks and workbooks.

In the aftermath of zero ban on inequality signs, questions that involve comparing and ordering numbers would no longer be symbolically penalized or criminalized for using the “>” and “<” signs (until further notice).

Below are a sample of three “uninhibited” Singapore math primary two inequality questions:

Which sign will you use, > or <?
(a) 45
42
(b) 81
71
(c) 317
407
(d) 734
724

Fill in the boxes with ‘<’ or ‘>’.
(a) 35
53
(b) 65
62
(c) 79
68

It’s not uncommon to see once-banned open-ended questions now gracing the pages of primary math textbooks, such as the following:

In 38 > 33 + ☐, what could the missing number be?

It looks like we’ve come some way in restoring the inequality signs in the (lower) primary school syllabus. Now that the mathematical resurrection of these symbols has taken place, does their confusion among schoolchildren still remain a concern for both teachers and parents?

An Inequality Quiz

Let’s end with a math quiz that tests our basic knowledge of inequalities.

1. How many types of inequalities in elementary school math are there?

2. Which metaphor(s) would you use to help children who are prone to mistake one inequality sign for another?

3. Name half a dozen math inequalities in real life that schoolchildren could relate to.

4. “An inequality is an equation that forbids the use of an equal sign.” True or False.

Symbolically yours

© Yan Kow Cheong, July 9, 2023.