John Hummel is bad at math.

Maybe, he’s mastered the basics. Maybe, he could zip through some derivatives.

But he is flinging magnificently hollow numbers in his campaign against Deschutes County District Attorney Patrick Flaherty.

“DA offices throughout the state typically exercise their discretion to not charge people arrested or cited by the police 3 to 10 percent of the time,” Hummel wrote in an email to The Bulletin. “Flaherty has put our community at risk by declining to charge people arrested by the police a whopping 40 percent of the time! This is the highest rate in the state by far.”

Before you start filling in the Hummel box on your ballot, look at what’s behind the numbers.

Hummel doesn’t know what the typical decline rate is for the state. His campaign only heard back from seven out of 35 district attorneys’ offices.

You’d think that would give someone who wants to be district attorney pause before claiming what is “typical” or that it’s the “highest rate in the state.”

It doesn’t stop Hummel.

He goes right on to claim the numbers mean one of two things: Flaherty is “either allowing dangerous people to go free or he’s derelict in not working with law enforcement to help them sync their police work with his charging philosophy.”

A district attorney needs to work with the evidence. Hummel makes that claim without providing evidence that either is happening.

Who are all these dangerous people who are going free?

Where is the evidence that he’s derelict in working with law enforcement?

Bend police officers endorsed Flaherty, not Hummel. The Des­chutes County Employees’ Association endorsed Flaherty, too.

In fact, when Bulletin reporter Shelby King contacted the Bend Police Department and the Deschutes County Sheriff’s Office, they said pretty much the same thing. You can’t know if the numbers mean anything without knowing the types of cases and the reasons they weren’t prosecuted.

“I have, both as a sheriff and as a citizen of Deschutes County, no issue specifically relating to decline rates from the DA’s office,” Sheriff Larry Blanton said. “I have talked with my detective, patrol and jail captains, and they don’t have any problems with the decline rates.”

The person with a problem with the numbers is Hummel. He misses and misleads.