Play this awesome Halloween math activity when motivation is low, spirits are high, and all your girl can think about is costumes, pumpkins, and candy.
Introducing the Perk & Petey pumpkin math activity. It basically takes something your kids are already super excited about (picking out a pumpkin and carving it) and makes it ten times more fun by adding a bit of mystery, whimsy, and plenty of hands-on math!

It’s a tough one to pull off in a classroom (believe me, I’ve tried!) but it is so incredibly perfect to do at home! Give your girl a week-long break from “boring” math and tell them to explore pumpkins instead.
They’ll love you for it!
Meet Perk and Petey
Perk is a big pumpkin. Petey is tiny. They’re best friends, and it is up to your child to discover their secrets.
Will they float or will they sink? How tall, how wide, how big around are they, and how much bigger is Perk than Petey? How many seeds do you think are inside each pumpkin–and how close was your guess? How much weight did your pumpkin lose after you carved him?
Your girl will get to know her new friends Perk and Petey (actual pumpkins that she will bring home from the store) as she estimates, predicts, counts, measures, compares, calculates, and more.
It’s math, but what it really feels like is the best kind of play. A dollop of real life, a hint of imagination, a fun holiday thrown in…it’s a math-tastic way to make the days leading up to Halloween even more fun!
Download the Perk & Petey Halloween math activity
The printable is set up to guide your child step-by-step through each pumpkin mystery, but here’s an overview of what you’ll find inside:
MATH MYSTERY # 1: WILL THEY FLOAT OR SINK?
Will Perk and Petey sink or float when you put them in water?
Hold on–before you toss your pumpkins in the bathtub, predict what will happen. Will they both float? Both sink? Will Petey float because he’s smaller?
Make your guess–then head to the bathtub and see if you were correct!
(This one is more science than math, but we’re just getting started!)

MATH MYSTERY # 2: HOW BIG ARE THEY?
How do you measure a pumpkin?
Clearly Perk is taller, but how much taller? Will you measure in inches or centimeters? What’s the name of measuring top to bottom, or side to side?

If you’re using a measuring tape, do you curve with the pumpkin or not? Where do you put the ruler, and what do you do if the ruler is too small to go across the whole pumpkin?
Measuring is trickier than it looks, and pumpkins have funny shapes that make it even more difficult. The challenges lead to some good questions and a hands-on problem solving.
Subtraction is the math for comparing anything, and there’s lots of comparing going on. How close was your estimate to the actual height? How much taller is Perk than Petey?
This is a really fun investigation, since kids love to see how much bigger one pumpkin is than the other!
Download the Perk & Petey Halloween math activity
MATH MYSTERY # 3: HOW FAT IS YOUR PUMPKIN?
How fat is Perk? How fat is Petey? The distance around the widest part is called the circumference.

Kids like learning about circumference because it’s such a hard-sounding word. It’s a cool thing to know how to do–and say!
Plus it’s also fun to discover how fat your pumpkin is.
Unlike height and width, which were measured in a straight line, circumference is meant to cling tight to a curved surface, with no gaps.
You can’t do this with a straight-edge ruler, but you can take a piece of string and wrap it around the widest part of the pumpkin. Cut the string and measure it to find the circumference of your pumpkin!
MATH MYSTERY # 4: HOW MANY SEEDS?
How many seeds are in a big pumpkin? How many seeds are in a small pumpkin? What do you think?

Finally–the part they’ve been waiting for: carving their pumpkins! But first, she’ll predict how many seeds are inside.
Prediction and estimation can be stressful for some kids. They are used to math being about right and wrong, and they don’t want to be wrong.
But estimation is such an important skill for number sense, so I’m going to show you how to make it feel safe and fun, even for anxious kids.
- Talk about estimation as “a guess”. Tell her she can’t be wrong in a guess; it’s just a game to see how close she can get.
- You guess too. Have everyone in the family take a guess. Who got the closest?
- Give her a benchmark. Hold up your hands and say, “This is about 12 inches.”
- Have her make her first guess is before she cuts open the pumpkin. She can “revise her estimate” once she looks inside, and again once she has counted about half of the seeds. (She can’t revise her estimate after that, though!)
- When it’s time for her to compare her guess to the actual number, say, “Wow, that’s pretty close! Do you think it helped to revise your estimate? Why did it help?”
When she’s done with that Halloween math activity, she can take a snack break by roasting pumpkin seeds! (Recipe included.)
Download the Perk & Petey Halloween math activity
MATH MYSTERY # 5: BEFORE AND AFTER WEIGHT
She has just one final task–a quick one. With all the carving and cleaning out, Perk and Petey have lost a little weight.

How much weight did they lose? Who lost more weight? How much do they weigh now?
It’s up to your girl to find out how much Perk & Petey weigh after their diet!
A Final Word About The Perk & Petey Halloween Math Activity
The Perk & Petey Math Activity is PERFECT to do at home, and it’s so much fun!
If your child is a bit freaked out by math, you can play down the “math” part and simply call it “the pumpkin project”.
The printable is geared to grades 3-5, but younger kids will love doing these activities as well. You may just need to help a bit with some of the trickier math, or be the scribe to write down her answers.
What did you think of this pumpkin math activity? Leave a comment and let me know!
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