Kristen Bell's Daughters Delta and Lincoln Hilariously Guess How Old She's Turning: '63' and '89'

Kristen Bell is ringing in her 39th birthday on Thursday, but her family finds her wise beyond her years.

In a video posted to Bell’s Instagram page on Wednesday, the Good Place actress’ daughters, Delta, 4½, and Lincoln, 6, play a round of guess-mom’s-age — to hilarious results.

“How old do you think I’m turning?” Bell asks her girls, who are kept off camera.

“Six… fifty…” Delta thinks out loud, before landing on “63.”

“How old do you think I’m turning, Link?” Bell asks her older daughter, who takes the over, answering “89.”

Bell then looks at husband Dax Shepard, who is also heard off-camera, and asks with a laugh, “Okay, Dad, how old do you think I’m turning?”

“I think a safe bet, somewhere in the middle of those two guesses, so… 71?” Shepard gamely replies, while Bell can’t help but burst into giggles. “Is that right?”

“I’m turning 39,” Bell finally reveals.

In her caption of the video, Bell said, “My kids are kind. I dont care if they cant do math 👵👵👵 (For my #armcherries : #fastmath is overrated.)”

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In addition to her birthday on July 18, the actress has something else to celebrate this month: the return of Veronica Mars.

The cult classic show — which originally aired on UPN and then The CW for three seasons — is being rebooted on Hulu.

Bell recently opened up about how Delta and Lincoln inspired her to sign on for the job, which required her to be away from them for long periods of time.

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RELATED VIDEO: Kristen Bell and Dax Shepard Had to ‘Work Really, Really Hard’ to Find Happily Ever After

“I’m here a lot of hours, which means, logistically, I’m away from my kids more hours,” she told Access Hollywood last week. “And missing four or five bedtimes a week. And when I decided to take it on I was like, you know what, now that I went back and reread the scripts and watched the show, I want my girls to have this character in their life.”

“Now I see why a lot of young girls and women said, thank you for doing that show. It wasn’t just because we entertained them, it was because she was a force in their life,” the Frozen actress went on, saying that Veronica is an empowering character. “She was an example.”

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The family recently returned from their annual summer vacation in Michigan, where Bell and Shepard are both from.

Both parents shared a rare photo of their daughters on July 4, shot from behind as the family gazes up at a fireworks display from the sand.

“Grateful for so many things today,” Bell captioned her post, while Shepard said, “Never been in a more magical setting for the festivities. ♥️💥♥️💥♥️💥♥️”