Metric Morning at E.M. Holt
Posted by William Benson on 3/11/2019
I had the pleasure of co-teaching with Ms. Strickland at E. M. Holt Elementary School last Friday morning. Ms. Strickland’s 5th graders have been learning about the metric system and metric unit conversion. After a review of the metric system and the meaning of the prefixes, students were presented with the following problem:
Josh and Katie are friends who are very competitive with each other. They both like to run, and they both want to be the one who ran the most each day. Today, Katie ran a 3 kilometer warmup, followed by 4 sets of 500 meters fast, and then a 4 kilometer cool down. Josh ran 2 kilometers to warmup, then 10 sets of 200 meters fast, and then a 5 kilometer cool down. Josh is sure he ran more than Katie since he ran more fast sets AND ran more to cool down.
Is Josh correct? If not, explain where he might have gone wrong or what he was missing using words and numbers.
Students determined what information in the problem was important. They decided that they would have to determine the total number of miles for each of the runners. They also were quick to point out that all of the distances would need to be in the same unit.
We talked about the importance of including units on numbers. Students had previously added a metric conversion table to their math journals. We also introduced students to the factor-label method of conversion:
3 km x 1000 m = 3000 m
Students took the lead in the final conversions needed to answer the question using multiple strategies (I am not sharing the answer in the event you would like to solve the problem.).
Research shows that student problem-solving ability improves when students are exposed to authentic, open-ended problems that require multi-step solutions and written defense of the solutions. All kinds of right here (and, kudos for including a running problem), Ms. Strickland! Great job! Thank you!!
p.s. Yes, Eli, I am pretty sure you would have a better time than me in a 100 m race, but I like my chances in a 15 km.