I volunteered this year to teach a math course at the private school where I help out for a few hours a week.

Now, as my calculus-teacher wife well knows, I have precious few higher math skills.

Nevertheless, when consumer math was raised as a possible elective, and I was assured that basic calculator functions could handle all the problems, I said I’d give it a shot – because I would have liked to have taken a similar course in high school.

Had I known more about credit cards, budgeting and getting loans, I might have avoided some financial errors starting out.

My students all have part-time jobs, so when I mentioned the difference between their nominal salaries and the actual net amount on their checks, they all nodded, and one said, “Yeah, they take out a lot for taxes, don’t they?”

So one important lesson has already been learned. I went on to Lesson 2, which was that the amount labeled “FICA” on the stub made me grateful to them, because Uncle Sam immediately adds it to my Social Security checks.

They apparently hadn’t known that, so I explained that when they reached my advanced years, they would have to count on younger people being willing to pay their benefits. They’re probably still pondering the likelihood of that eventuality.

But reading that The New York Times printed a story this week that should have been headlined “Donald Trump Obeys Law by Using Losses to Offset Gains” made me think that those who criticized him for doing that 20 years ago have probably never once (except by error) paid one thin dime more in taxes than the law required.

Sure, Trump should have already released his most recent returns, and he almost certainly isn’t the tax-law “genius” that Rudy Giuliani made him out to be (he did, after all, lose $916 million in 1995).

But he is only one of the estimated 1 million business owners who annually use a tax code feature (hardly a “loophole”) that allows losses in a single year to offset income in that year or a span of years before or after it.

This is not “avoiding” taxes, as some have claimed. In order to avoid them, you have to owe them to begin with.

The real lesson being taught is that if you have offended leftists, they will paste a target on you. Conservatives (Trump occasionally approximates being one) have already felt the impact of a weaponized Internal Revenue Service and a thumb-on-the-scales-of-justice FBI, and now we see the left stealing private information and then falsely twisting its meaning.

As columnist Megan McArdle wrote on Bloomberg.com Monday, being able to claim such losses is vital for businesses of all sizes.

If a business lost $1 million in one year and made a profit of $1.5 million in the next, she noted, it could face a potential tax bill of $600,000 the second year and have only $500,000 in profit to pay it.

Not allowing losses to be deductible over a span of years would be inherently confiscatory – and ruinous to the businesses affected by it.

Which is why the oh-so-righteous owners of The New York Times were able to earn a profit of $29.9 million in 2014 and pay no tax on it whatsoever, offsetting it with previous losses (and even getting a $3.5 million refund for the year).

And while a billion Georges is a substantial loss, the Washington Times reported in 2014 that the State Department lost $6 billion “due to the improper filing of contracts during the past six years, mainly during the tenure of former Secretary of State Hillary Clinton, according to a newly released Inspector General report.”

The IG report said the loss posed a “significant financial risk and demonstrates a lack of internal control over the Department’s contract actions.”

At least Trump only lost his own money. Clinton lost ours.

Taxes may be “the price we pay” for civilization, as Justice Oliver Wendell Holmes claimed, but recent experience – including the example above, and many more (Obamacare! The stimulus! The $20 trillion national debt!) – shows we have gone far beyond what is necessary.

The basic principle was expressed by Judge Learned Hand, who wrote, “Over and over again the Courts have said that there is nothing sinister in so arranging affairs as to keep taxes as low as possible. Everyone does it, rich and poor alike, and all do right, for nobody owes any public duty to pay more than the law demands.”

Besides, it’s a dead cinch we can spend our own money better than government can. Which is why its pound of flesh should always be kept to the minimum necessary.

As I tell the kids, it’s never too late to get your budgets under control.

M.D. Harmon, a retired journalist and military officer, is a freelance writer and speaker. He can be contacted at:

mdharmoncol@yahoo.com