Conservation refers to the idea that certain physical attributes of an object remain the same, even when its outward appearance changes. From a pitcher, we asked the children to pour 100 mL of water into a small beaker. The water level nearly reached the top! While our group watched closely, a student poured the water from the smaller beaker into a much larger cylinder. In this container, the water barely covered the bottom! “So which beaker contains the most water?” After more measuring, pouring, and comparing of the heights and widths of the beakers, the children agreed that both containers were holding the same amount of water!
In similar activities, we estimated how many marbles and beans it would take to fill the smallest beaker. After counting and finding the actual numbers, we poured the marbles or beans into larger containers. Again, in the tall, narrow cylinder, the marbles almost reached the top, while in the much wider beaker, they barely covered the bottom. Although the taller cylinder appeared to be fuller, both beakers contained the same number of marbles or beans!
Understanding the idea of conservation of number, length, mass, liquid, and capacity require logical thinking skills that develop gradually over time. We first explored these concepts back in November. Although it is tempting to focus on only one detail such as the length of the row of cubes, the position of the rulers, the shape of the piece of playdough, or the level the water or marbles reach in a cylinder, our students now also consider other important facts when assessing quantity, mass, and capacity. We believe that children progress through specific stages of development at their own pace, and it is very exciting to notice how this aspect of their cognitive reasoning has grown during the past six months.
Merci et bonne journée !