Agnes Zhelesnik, aka America's Oldest and Beloved Teacher, turns 100 today...

NORTH PLAINFIELD, N.J. -- They say you're never too old to learn, but here at the Sundance grade school in North Plainfield, N.J., they're proving you're never too old to teach, either.

"See my two legs? They still move."

That's home economics teacher Agnes Zhelesnik, but the kids just call her "Granny." It's a nickname she comes by honestly, as the oldest living teacher in America. She turns 100 on Sunday.

Asked how old that is, one student says, "Very, very, very, very old."

Says another: "I know people can get very old like that, but I wouldn’t think that Granny would do it -- even without a wheelchair." 

Agnes Zhelesnik shows Steve Hartman around her school.

 CBS NEWS

 Without a wheelchair -- or any chair for that matter -- Agnes puts in a full day's teaching, five days a week. She hasn’t burned out on the job, partly because she hasn't been doing it that long. She was a homemaker most of her life.

"My husband didn’t approve of working -- he wanted me to watch the children," she says.

So she did, then she watched the grandchildren, then she played a lot of bridge. That got old, and she still felt young, so Agnes started working here at the age of 81. Today, she's so devoted to these kids, she hasn't even called in sick since she was 98.

"I just think she loves the children," one student says. "She puts the love into her cooking." 

Can you taste the love?

"No, you cant taste love, but you can feel love," the student says.

"And all the children love her, because she's so nice, so compassionate," says another. "She perseveres a lot." 

Students threw Agnes a party to mark her 100th birthday.

 CBS NEWS

 For those reasons, and a hundred more, the kids threw her a huge birthday party -- not a retirement party, mind you. She'll be back on Monday and hopes to keep working for years to come.

"What else is there in life?" Agnes asks. "Children make the whole world."

Or, at the very least, make your day.