Pom Math

My children like math, but they dislike trying new foods. So, anytime I can connect math to food, there is the slim possibility of eating…even liking…something new. Pomegranates are not a common food in my kitchen, and I’ll admit to being intimidated by them. That seemed good enough reason to buy a couple to see what might happen.

First and foremost, this activity is just fun. If it happens to get mathy when you do it, pat yourself on the back and call it a day.

1. Get a couple pomegranates: This is the easy part. The grocery store should have them. Especially at this time of year.
2. Hand a pomegranate to your kid: Let your child hold one. Is it heavy? Is it light? What does the outer skin feel like? Smooth? Bumpy? What color is it? Challenge your kid to observe as much as she can. Make sure to note the produce stickers that might be on your pomegranate. Where do pomegranates come from? (We’ll call this step of the process a “science-y moment.”)
3. Imagine what is inside: If this is the first time your child has been introduced to a pomegranate, ask him to imagine what the inside of it looks like. Perhaps your kid would even be interested in drawing a picture of what he thinks it will look like. (An artsy moment!)
4. Cut it open: Slice that fruit in half. Let your child wield the knife. (Seriously, let your kid take appropriate risks and learn some kitchen skills and safety.) Oh wow! Is that what she expected to see?? Why does it look like THAT? Okay, now the math fun begins…Note: For those concerned…I asked my son to pose with this knife in the pic above. Three things were different during the actual cutting of the fruit: he moved his thumb, I made the initial cut into the tough smooth skin, and we cut it in half along the other axis.
5. Check out the pattern you see in the way the seeds are packed: Count the arms of the spiral that grow from the center of the fruit (see the pic at the beginning of this post.) Why do the seeds grow this way? This part is very cool, but may take several iterations of similar activities to drive home. The number of arms on the spiral should be a Fibonacci number. I counted 8 on my pomegranate. Fibonacci numbers are interesting because they pop up often in nature. As a student, I  don’t remember learning about Fibonacci numbers…but these kinds of patterns and number play are the fun, inventive, creative, engaging part of math. Start pointing them out to your kids. Even if (especially if) you don’t feel entirely comfortable with them. More on Fibonacci numbers is at the end of this post.
6. Pull out a single seed and observe it: Maybe even pull out a magnifying glass. What shape is the seed? Why THAT shape? Why not something else? (The shape of a pomegranate seed is called a rhombic dodecahedron. Rhombic because when you look at a single face, it is 4-sided and elongated like a diamond, a.k.a. rhombus. The “dodec” part of “dodecahedron” means 12. It might drive you crazy, but you can count 12 sides on that itty bitty seed. This shape allows the fruit to pack a lot of seeds into a tight space.)
7. How many seeds are in there anyway??: Maybe you have a child who is interested in counting each and every one. Okay. That should give you time to clean the kitchen, maybe even a few other rooms. Maybe your child is ready to learn or apply estimation skills (an important skill in the process of developing number sense and mental flexibility.) FYI, you can assume there are at least 500 seeds in there. Jewish tradition says there are 613 and that each represents a commandment in the Torah. (If you’d like to expand your exploration of the pomegranate, there are numerous cultural connections and symbolism to note about this fruit.) BTW, here’s how to get all those seeds out easily:  Fill a big bowl (preferably clear so you and your kid can see) with water. Begin to pull apart the pomegranate membrane from the seeds in chunks. Notice how the seeds sink and the membrane floats? Voila! Easy separation. Just skim the membrane pieces off the top, leaving the seeds at the bottom.
   

   

   

   
8. Play number games: If your child is pre-school or early elementary age, pull some seeds out of the bowl and start playing with them. For example, take a group of 10 seeds and ask your child to regroup them…2 and 8, 7 and 3, 2 and 2 and 6, etc. etc. Or reach into the bowl and pull out a small handful of seeds (no more than 20). Ask your child to reach in and try to pull out the same number of seeds from the bowl. Compare handfuls. Do they look approximately the same? Are they exactly the same? Keep trying to pull out the same number. If your child continues to show interest, continue coming up with questions. If interest is waning, move on to the next step…
9. Eat them: Yes! Eat them! They are juicy and crunchy and yummy. And now that your child has become intimate friends with them, he will be more likely to try one. Put ’em in your oatmeal or on your salad or in your martini…uh, I mean your yogurt. The 5-year-old threw a bunch into the blender to make juice. He took a sip of the unsweetened liquid (slightly diluted with a bit of water) and declared it dee-licous! So, I am patting myself on the back and calling it a day.

(Mathematically…playing around with food and cooking is always a recipe for a mathy moment. In this case, there are a number of ways to access mathematical concepts and mental flexibility while estimating and counting and grouping seeds. If you want to get into the Fibonacci connection, know that the Fibonacci sequence is 0,1,1,2,3,5,8,13,21,34,55… Each term after the first 1 is found by adding the two previous terms together. 1 + 2 = 3, 3 + 5 = 8. etc. You can google all kinds of information about how the Fibonacci sequence pops up in nature and activities to do with kids. If you are a Ted Talk fan, check out this one about Fibonacci numbers.)