At a White House event last summer, Donald Trump boasted, “We’re going to get the drug prices down — not 30% or 40%, which would be great. Not 50% or 60%. No, we’re going to get them down 1,000%, 600%, 500%, 1,500%.”

The president said “nobody else” was capable of such a feat, adding that he’d produce “numbers that are not even thought to be achievable.”

Oddly enough, he had a point — but not the one he was trying to make.

If the price of a product is reduced by 100%, that means it’s free. If the cost of prescription drugs is cut by more than 100%, it means the medications would just be free and pharmaceutical companies would be paying consumers to take their products.

Or put another way, when the president said these are “numbers that are not even thought to be achievable,” he was correct, but not in the way he intended.

This came to mind on Thursday night, as Trump launched his TrumpRx.gov website. The New York Times noted:

President Trump again repeated a mathematically impossible claim that this program would reduce drug prices by “300, 400, 500 or even 600 percent.” A 100 percent discount would be a price cut to $0. For example, when listing weight loss drugs that would receive discounts, Trump said that it would cut “the price of Wegovy from more than $1,300 to $199, a 578 percent difference.”

No, really, that’s what he said.

This isn’t that complicated. If the cost of a medication goes from $1,300 to $200, that’s a roughly 85% reduction. We know this because the math is straightforward: 1,300 minus 200 is 1,100, and 1,100 divided by 1,300 is nearly 85%.

I’m not sure how, exactly, he arrived at 578%, but (a) it’s wrong; and (b) he should’ve known it’s wrong, because a 578% decrease in the cost of a consumer product is literally impossible.

The larger problem, however, is that the Republican appears wholly unaware of his difficulties with arithmetic, which tends to be a problem. For example, he often uses the word “trillion” in ways that suggest he doesn’t understand what it means.

Trump also tried to justify his deadly military strikes on civilian boats in international waters by saying that 300 million people died from drugs in the United States in 2024 — a total that was off by almost 300 million.

This is the same president who’s so confident in his mathematical expertise that he has come up with international trade tariff rates based on formulas that only exist in his head. That’s obviously unwise, but it’s especially problematic given his unfamiliarity with how numbers work.

I’m often reminded of something Bill Lueders wrote for The Bulwark last year: “Whatever the claim, the president has the numbers to prove it, even if he has to make them up.”

It remains an important detail. The incumbent president doesn’t use numbers and statistics like an adult; he uses numbers and statistics that he thinks sound good and make him feel better.

This post updates our related earlier coverage.