Washington (CNN) For President Donald Trump , a big inaccurate number is almost always preferable to a slightly smaller accurate number. Even when the truth is in his favor, Trump tends to choose the lie.

Take prescription drug prices. They went down last year for the first time in 46 years, according to the Consumer Price Index.

"First time in 51 years that drug prices went down," Trump said in Ma y. "First time in 53 years," he said at an event with Pakistan's prime minister on Monday.

Or take the unemployment rate for women. For three months, it has been at its lowest level in 66 years.

"With women, we have the best numbers we've had in now 71 years," Trump said in May . "Women: 75 years," he told his Cabinet last Tuesday.

Preliminary data released last week showed that overdose deaths had declined in 2018 for the first time in 28 years.

"It's dropped for the first time in more than 30 years," Trump said at his rally in North Carolina last Wednesday.

Trump's penchant for dishonesty is well-established. His rhetoric is littered with major fabrications, entire stories he seems to have invented out of thin air. But his remarks are also peppered with extremely trivial exaggerations, slight stretches about accomplishments that would seem not to need any deception to shine.

It sometimes seems as if he has set his Teleprompter to automatically translate the word "almost" to "more than." When the unemployment rate was the lowest in 49 years, Trump boasted of the lowest rate in "more than 50 years." When he had confirmed 91 new federal judges, he claimed "more than 100 new federal judges." When the country had added 481,000 manufacturing jobs since his election, he touted "more than 500,000 jobs."

It's possible that Trump simply can't remember some of the accurate figures. But his exaggerations come not only in impromptu musings but when he is mostly reciting a prepared text. Though he occasionally cites the correct numbers, he embellishes so consistently -- and so consistently avoids the use of any figure that is lower than the true figure -- that we're confident it is intentional.

This is simply what the man does.

It has, after all, been his pattern for decades. Before Trump was exaggerating his poll numbers and the size of his rally crowds, he was exaggerating his wealth , his television ratings , the size of his buildings . As a developer, Trump was famous for marketing his properties as if they had many stories more than they did: "52" for a 44-story building, "90" for a 70-story building, "68" for his 58-story Trump Tower.

He even wrote about his fondness for overstatement in The Art of the Deal, the 1987 book he co-authored with Tony Schwartz. Trump described his boasts as "truthful hyperbole, "an innocent form of exaggeration," and "a very effective form of promotion."

As President, at least, the incessant exaggeration seems more pernicious than innocent. By choosing to be consistently untruthful about even the things on which he would seem most easily able to be truthful, Trump undermines his credibility about everything else. And, of course, the misinformation results in millions of people being misinformed.

But it still does seem to be an effective form of promotion.

Trump knows that many of the false figures will be broadcast straight to voters unfiltered, through Fox News or another friendly outlet. Even when the false figures are fact-checked, the act of correcting him means the media has to amplify the underlying accomplishment. ("Actually, the unemployment rate for women is the lowest in 66 years, not 75.") And if his supporters happen to see this kind of correction, they might well view it as biased nitpicking -- an example of a media obsessing over trivialities to avoid giving him his due.

For proponents of truth, the hardest Trump falsehoods to challenge might be the smallest ones.