## Benefits of Metric-only Measurement Instruction in Education:

**Reason 3: Working Memory**

One of the leading researchers in working memory is Dr. Todd Rose. He is part of the Harvard Graduate School of Education, and co-chair the summer institute for Mind, Brain, and Education. Working memory is the system that actively holds multiple pieces of transitory information in the mind, where they can be manipulated. This involves execution of verbal and nonverbal tasks—such as reasoning and comprehension—and makes them available for further information-processing (Becker, J. T., Morris, R. G. (1999). According to Rose, a child’s working memory is considered the number one predictor of academic success!

Moreover, according to Rose, many people think of their memory as a cup, filling up with water; they believe that when that cup is full, any new water (or knowledge) simply falls to the sides, while they retain all the water (knowledge) captured in the cup. This notion is false. The research suggests that when the “cup of memory” is filled up, any new water (knowledge) tips it over and the student loses all of the knowledge gained and must start over at a later time.

The idea of the cup is critical to understanding and reforming mathematics education. As previously discussed, in the U.S. we practice dual-measurement instruction. Now, lets apply this practice to working memory. Imagine what happens when a student tries to master the mathematical concept of area, the amount of space inside a flat (2-dimensional) object like a triangle or circle.

We first require the student to learn the concept of area using customary units. Then we require them to recalculate the formula using metric units. Although the formula is the same for the same shape, the act of changing units of measurement to an unrelated, usually unfamiliar system, makes the student’s memory work even harder. And the mathematical conversions and memorized conversion factors required to covert between units strains the brain even more. To the student, the concept of area becomes ALL three (1.calculate answer using customary units, 2.calculate answer using metric units, 3.convert customary units into metric units then calculate the answer) of these steps. **All three of those steps might be parts of the overall learning objectives for the day. However, all three of those steps are NOT needed for a student to learn the concept of area. A young student can not recognize this critical difference!**

*For many kids, this exclusively American practice is overwhelming to their memory “cups.” Sadly, for countless students, this complete loss of working memory happens while they are trying to learn the most foundational parts of their math and science curricula.*