Any competent business owner should know how to do a cost-benefit analysis and simple accounting. But Donald Trump doesn’t seem to understand the need to put a pencil to paper from time to time, just to be sure the numbers add up.

Here’s Trump in a recent town hall meeting, answering a question on the national debt:

“We owe $19 trillion as a country,” he said. “And we’re going to knock it down and we’re going to bring it down bigly and quickly, we’re going to bring jobs back, we’re going to bring business back, we’re going to stop our deficits, we’re going to stop our deficits, we’re going to do it very quickly.”

Setting aside the issues of grammar and usage, the question Trump begs is how? How will we “stop our deficits” and reduce the national debt?

He responds by saying he’ll cut the Department of Education and the Environmental Protection Agency. Fine. But that’s small change, compared to the national debt. The budget for the Department of Education last year was $77 billion. The budget for the EPA was just $8.1 billion. The deficit (remember, each year’s deficit contributes to the overall national debt) last year was about $440 billion.

“Trump wants to come across as a deficit and debt hawk,” writes James Capretta for National Review. “He has said repeatedly that the nation’s governmental debt is an indication of the incompetence of current and previous elected leaders. He rails against the budget deal struck between outgoing House speaker John Boehner and President Obama because it increased appropriations spending on defense and domestic programs in 2016. He hasn’t exactly promised a balanced budget, but he has said federal debt is a major problem he would address as president.”

But he refuses to address the real causes of deficit spending – entitlements.

“On entitlements, Trump is essentially in agreement with most Democrats,” Capretta notes. “He says he won’t make any changes to Social Security or Medicare benefits. In previous years, he also said Medicaid shouldn’t be cut. He says he now favors converting Medicaid into a block grant to the states, although he has not promised that this switch would reduce federal costs.”

Trump has also said he will save money through clever negotiating.

“Trump said he would find $300 billion in annual savings by negotiating down the prices Medicare pays for prescription drugs,” Capretta writes. “This is, itself, problematic, given that such spending only amounts to $80 billion per year.”

And Trump pledges to repeal the Affordable Care Act – which is a good start. The problem is that he then goes on to promise to cover everyone.

“I want everyone to have coverage,” Trump said. “I love the free market, but we never had a free market.”

Now, Trump is right that the health care industry is not a free market system; government controls too much of it. But the answer to that is less government, not more.

Trump’s numbers just don’t add up. As a businessman, he should see that.