Developing Students’ Initial Understanding of Area Measurement through the Unit: Teaching Experiment on a Lesson with Cashewnut Cookie Context Conducted In Third Grade Students of Elementary School

We examined way of helping fifteen third grade students of class 3A in Elementary Laboratory School of Surabaya State University to understand the area measurement through the unit concept in a first lesson of our instructional sequence of teaching experiment. We used the cashewnuts cookie context and set three kinds of activity. First activity highlighted some unit issues through investigation: overlapping units, gap and leftover. Second activity concerned on the emerging students’ insight on relationship between the number of unit and the area of a surface. Third activity concerned on measuring and comparing the surface by the use of units. The results indicated that the students need a clear situation of task in activity 1 through discussion. The part of discussion takes crucial role around the task. We noted that missing this discussion part steered the students to confusion. The confusion leads to the failure of students’ acquisition of understanding of units issues: overlapping, gap and the effect of each issue. However, we found the second activity could promote students to finally recognise the unit issue. The students also emerged the connection between the ideal size or area with number of units used through the activity of making ideal size of cookie for given fourteen nuts. The activity three could help students to recognise the use of units to find the area in a strict regard of overlapping and gaps through measuring the cookie with the nuts. The students could also compare the area by the use of those units. Keywords : area measurement, unit, overlapping, gaps, measuring, comparing