(NBC) -- Lori Mackey has a difficult enough task making her argument to small children.

Mackey says "10% for savings, ten percent for investing."

With her re-designed piggy banks and workbooks for parents, the author and mother is all about how to save, stay out of debt, and prepare for adulthood.

Lori Mackey says "you spend one hundred percent of what you have, and you're gonna struggle the rest of your life."

But can her message work on a teenager? After all, from the prom to the next football game to graduation to college, saving is not at the top of their priority lists.

Credit cards, says Mackey, were a game changer. With parental co-signers, even the youngest teens now have access and dropping plastic is very different from spending a hundred bucks.

She tells parents: make sure the cash is there before the credit is spent and if they can't make the distinction, don't sign.

Lori says "bad credit is going to stay with them for more than ten years."

When asked why should a teenager be concerned about credit, Lori says "because they got it so early."

In the last decade, the number of incoming college freshmen with credit cards has tripled their average debt now at $1,585.

Mackey says parents should use their own misadventures with credit as a launching point for discussion.

Parent Kathleen Hill says, "I made that mistake when I was eighteen."

Hill vividly recalls the card application she received in the mail.

Kathleen says "I said, 'This is great,' and I went to Maui with a girlfriend."

More than $3,000 later, Hill finally paid her card off. But she's not afraid to let sons Cody, 18, and Tanner, 14, know what she did wrong.

"Credit isn't money, credit is creating debt," 18-year-old Cody Hill says.

That's the message parents need to send, says Mackey, because they're not going to get it from peers, from schools, and especially advertisers.

Lori says "you will spend 10-18% more on credit than you will with your cash."

College student Cody doesn't own a credit card, and he's curtailed a favorite hobby, video games, because he's between jobs right now.

Fourteen-year-old Tanner Hill says "I'm pretty much just going to save any money that I get."

Who says you can't teach a teenager to stay out of debt?