From Mary’s Teaching Toolbox
One of my favorite activities to do with pumpkins is to estimate and count the seeds. Pumpkins generally have too many seeds for them to all be counted one at a time, often over 500. While this number is too large for preschoolers to understand, there are some excellent number lessons that are just right for preschoolers that can be done with the seeds.
Estimating in Preschool
Preschool is not too early for children to start learning about estimating. Estimating is different from a guess. Estimating involves predicting a value based on known information. If I asked you how many shoes are in my closet, you would need to make a guess since you don’t know if I’m a minimalist or Imelda Marcos (I just dated myself, so if you don’t know who she is, google “Marcos and shoes”). If I showed you a picture of my closet then asked the same question, it would be an estimate since you have some relevant information to use.
Young children need to be introduced to estimating because it helps to develop their number sense. Learning to estimate smaller numbers now, will help them estimate larger numbers later. It also helps them to think about numbers in a different way than counting sets.
Preschool children often believe that there is only ever one “right” answer to any question, but for estimating this is not true. Its important to explain that an estimate does not need to be exactly right to be a good estimate. I explain that a good estimate is anything that is not silly. This can be illustrated with a snack bag of goldfish. It would be “silly” to think there are only two in the bag, so two is not a good estimate. However I could estimate 16, 24, or 30. All 3 numbers could be a good estimate. The goal is to get as close as you can. You can get better at estimating by practicing.
That said, always accept a child’s estimate even if it is wildly off. If the child is giggling, or acting silly when they make their estimate, I may remind them that good estimates are not silly. If they keep their estimate, I just let it go and continue with the activity. They may not yet be ready to estimate or need more practice before they understand what is expected.
The best way I’ve found to teach children to use relevant information is to use a benchmark. A benchmark is a set of the same type of items with a known quantity. Children as young as 3 can usually tell you which of two distinctly different sets is larger or smaller. Estimating using a benchmark builds on this.
First have the children count the seeds to make their benchmark. By counting them, they will develop a better understanding of how many are in the set. Ten is a popular benchmark, but 5 would work as well, especially for children who are still working on the numbers 1-10. I like to use cupcake liners for the children to put the seeds into. Next decide if the set you’re estimating is larger or smaller than the benchmark. For some children this may be the only estimate you want them to make. .
Children who can name numbers that are larger or smaller than the benchmark being used can then estimate an exact number. Using a number line can help them make their estimate.. Put a dot on the ten (or whatever benchmark you are using), larger numbers are on one side and smaller numbers are on the other. Do you estimate the number to be close to 10 or a lot smaller/bigger? Can you make more than one group the size of the benchmark? While a benchmark of 10 can be used to estimate sets up to and over 100, keep the sets smaller than the number to which the child can count. Children need practice estimating smaller quantities before they move to larger ones.
Finally have the child count out the seeds they estimated. Is it more or less than the benchmark? Was their estimate close? If they are interested give them another pile of seeds to estimate using the benchmark they already made.
If you want to find out how many seeds were in the whole pumpkin, keep track of how many seeds each child counted and put the counted seeds to the side. While the total number is almost surely beyond the understanding of most preschool children, they like to know how many there are. When I taught kindergarten, we put all the seeds into groups of 10 and then I introduced counting by 10’s to find the total number. With younger children I just keep track and tell them at the end. We always talk about how counting all the seeds would be too hard for one person, but when we all work together it is easy!
Think carefully about the size of your pumpkin if you’re going to try to count all the seeds. I used a small Pie Pumpkin and it had 237 seeds in it. Large carving pumpkins often have even more than that.
Be sure to clean and keep the seeds for another activity. Some ideas include: material for loose parts, roasting and tasting, collages. In a future blog I’ll be sharing about using the seeds to measure.