A day after our Forest Day field trip first grade teacher Ms. Leena discovered a big bag of pine cones and spruce cones in the first grade classroom. The first graders and Ms. Leena came to the conclusion that the cones must belong to their class mascot, Oscar. Ms. Leena emptied bag of cones onto the floor and asked what would be a good way to count all those cones. One pupil suggested counting the cones by 2’s but Ms. Leena said that that could take a very long time. The next suggestion was that they count the cones by 10’s which sounded like a really good plan.Ms. Leena asked three children to each count out a pile of ten cones. Then together the class counted the cones in each child’s pile by 2’s. Finally they counted by 10’s how many cones they had in piles altogether. They discovered that there were 30 cones in three piles. Three more children were asked to each count out piles of ten. This time there were 60 cones in six piles of ten.
Four more children each counted out piles of ten cones and the children checked that there were indeed ten by counting them by 2’s. This brought the total number small to ten piles of cones. When the children counted the ten piles by 10’s they learned that they now had one hundred cones! All of the ten piles were pushed back together to form one pile of one hundred cones.
By the time that every child in the class had had a chance to count out a small pile of ten cones, the first graders realized that there were seven piles of ten and one pile with one hundred cones in it. They counted, “… one hundred, one hundred and ten, one hundred and twenty, one hundred and thirty, one hundred and forty, one hundred and fifty, one hundred and sixty and one hundred and seventy.” It was very interesting to find out that Oscar the squirrel had hoarded 170 cones in their classroom!