Estimation means an opinion or judgment. Room 102 is practicing estimation. Students are learning estimation is more than just "taking a guess". It is reasoning to find a useful estimation.
Time spent “teaching” students to estimate, and evalate estimations, is valuable. These types of activities are critical in students’ development of number sense. They provide students the opportunity to learn and hone a skill that they will use in the real world. Mental computation is an important part of number sense.
To avoid wild guesses and to create a foundation for understanding, students used a benchmark to estimate the eggs in the jar. In mathematical estimation, the benchmark is usually a set of 10 of the presented objects in a second identical container labeled "This is 10." This jar will give students a frame of reference to make a more accurate estimate.