How Many is 100?

Although it feels like we will never get here (with all the snow days we've been having lately), the 100th day of school is just around the corner. We started school in mid-August, so if you started after Labor Day, don't worry you'll be there before you know it. I know, some of you are thinking, big deal, it's not the end of the school year or anything (although every year I have one or two little kindergarteners that think they'll be moving on to 1st grade on day 101). But in all seriousness, the 100th day of Kindergarten is a big, hairy deal. One of our Virginia State Standards and a Common Core Standard in Kindergarten is to count by 1s and 10s to 100.

Each day of Kindergarten begins with a 10-15 minute calendar lesson, which includes counting the days of school. When we get to day 100, we celebrate all we've learned so far during the school year, especially counting to 100. We've been studying the hundreds chart and learning about number patterns for skip counting by 5s and 10s in math for the past couple of weeks, so for practice, we send home an assignment for each Kindergartener to bring in collection of 100 of the same small item in a quart sized Ziploc bag labeled with his/her name. On the 100th Day of School each child shares his/her 100 items with the class and we compare what different collections of 100 items look like. Students usually bring in small items such as marshmallows, pennies, macaroni noodles, etc. This year since my son is in Kindergarten, I was on the at-home side of this project. So, I thought, I'd share how I got him to count a collection 100 Lego's.

First of all, not all students can count to 100 by this point in the year. Yes, we've been counting the days of school since the beginning of the year, and many students are able to count to 100. However, we all learn in different ways and at different rates, so some of my students are just not there yet. It's also really hard for a 5 or 6 year old to count 100 objects without losing track. Most kiddos at this point have 1-1 correspondence with counting objects to 20 and those that can count to 100 are rote counting (counting based on memorization through repeated practice). All students can at least count to 10 and 10 is an easy number to keep up with, therefore, when trying to count 100 objects, I strongly recommend grouping objects by 10s to count them. Also, it's easiest to get little ones to group objects when they have a defined space. So, before I had my son start counting, I counted out 100 Lego's myself and placed them in a small plastic container.

Next, I drew 10 circles on a large sheet of easel paper, since 10 groups of 10 is 100. The circles provided him with clear boundaries for each group.

Then, I gave the hard work to my son. I told him we had to count out 100 Lego's for his homework project. So, I said, "We are going to make this easy by counting to 100 by 10s. Can you count and put 10 Lego's in each circle?" He counted out 10 Lego's for the first circle, then being the 5-year-old boy that he is, my son said, "So, do I just put a handful in each one?" I guess he thought this was going to be too time consuming for him, so he would try to figure out a short cut. I told him we had to have exactly 100 and although he could put a "handful" in each circle, he was going to have to count to make sure that he had 10 in each circle. He dutifully put a small handful in each circle and then touched and counted each Lego to make sure he had 10 before moving on to the next circle.

After, he finished filling in all of the 10 circles with 10 Lego's, I asked my son to go back and count by 10's to make sure we had 100. Of course, he perfectly touched and counted each group by 10s to 100. "10, 20, 30, 40, 50, 60, 70, 80, 90, 100."

Then, I pulled out the quart sized Ziploc baggie and told him we have to double check our answer and count each handful of 10 as we place it in the bag.

Another, perfect count. We definitely have 100 Lego's in our bag. My son and my students will be comparing collections of 100 items at school, so if you are completing this activity at home, I highly recommend counting 100 of 2-3 items and placing them in containers that are the same, so that you can compare what 100 looks like. For example, 100 Lego's looks much different than 100 grains of rice. This also helps your little one not only practice skip counting, but you're also activating other skills that will help with estimation and comparing sizes and numbers in the future.

Happy counting!