Donald Trump is using simple mathematics to his advantage as he continues to make giant strides towards the Republican presidential nomination, USA Today reported.

On Tuesday, in a classic case of irony, Trump won by losing, according to Sam Wang, a Princeton neuroscientist who has gained reputation since 2004 for having predicted U.S. presidential elections based on math, including coming within one electoral vote short of the exact 2008 presidential election results.

Trump lost to Ohio Gov. John Kasich in the latter's home state but won the primaries in five other territories—Florida, North Carolina, Illinois, Missouri, and Northern Marianas.

Wang explained the Trump gambit this way: Kasich's victory in Ohio kept the governor in the race, keeping his rivals splintered and preventing Texas Sen. Ted Cruz from maximising his electoral strength.

Wang said that based on numbers, Trump fares better in a three-way race than in a head-to-head duel with Cruz.

As such, those who voted for Kasich in Ohio, "indirectly" voted to support Trump, he added.

The poll expert noted that Trump's unpopularity rating—minus-30 or more in some polls—would make it hard for him to get a majority of delegates in a head-to-head duel with Cruz, he said.

"Trump is pretty unpopular," Wang said. "He's less popular than Ted Cruz."

If Kasich did not win Ohio, the governor would have quit the race. With Sen. Marco Rubio having also dropped out of the contest, Cruz would be in a position to better challenge Trump, one-on-one, since the votes, intended for Kasich and Rubio, or at least some huge chunks of them, were expected to go to Cruz.

If Kasich truly wanted to stop Trump, he should stop campaigning in some states to allow Cruz to win and pick up the delegates in those states, Wang said.

Politically that might sound absurd, but mathematically, it isn't, the numbers expert said.

As it is, Wang put Trump's odds of getting the GOP nomination at 90 percent.

However, Wang said if Trump vs. Clinton materialises in November, the odds for Trump remain unclear.

Nevertheless, Wang said Clinton has the edge in the general election based on an economy that's not in recession and President Barack Obama's improving approval rating.

"The better the approval rating, the better position the president's party is in," Wang said.