Math - Metric Conversion Trick

When I was subbing in 6th grade I was able to teach a fun lesson about metric conversions.   We read a story and introduced a sentence to help students remember the order of the metric units.  The original story was a little different than the one below.  It used the sentence "King Henry Does Usually Drink Chocolate Milk," but the students and I decided that was a boring sentence and we preferred the more interesting one that read, "King Henry Died Unusually Drinking Chocolate Milk."  So I edited the story to fit our memorization tool sentence.  Then when I subbed in 4th grade and taught the same lesson, I decided to make this detailed chart which is a mix from the math textbook and things I've learned from other teachers.

Click HERE to go to Google Drive and print the PDF file. (Note, I do not allow people to access the PDF for editing)

Click HERE to access this chart in Google Slides for editing purposes.  PLEASE MAKE YOUR OWN COPY BEFORE EDITING IT.

The arrows at the bottom of the chart show kids that you DIVIDE by ten when you are converting toward the larger units (I say "toward the giant") and that you MULTIPLY by ten when you are converting toward the smaller units (I say "toward the tiny bug").  I gave each student a copy of this chart.  The giant and tiny bug references are from the story listed at the end of this post.

Another trick to show the kids when to multiply or divide by ten involves using your arms.  True, I probably looked like a crazy person teaching the kids, but it really worked.  When you are converting from the smaller units to the larger units, you stick your arms out wide (like you are stretching bigger).  The outstretched arms look like a division symbol.  When you are converting from larger units to smaller units, you cross your arms in front of you putting one arm on each shoulder so that it looks like an "x" for multiplication.  For each square you move in whichever direction you will either multiply or divide by 10.  I tell them that 10 is the magic metric number.  I put the chart up on the smartboard/doc cam and literally did the arm motions and walked back and front of it to show kids how to do it.

The following story about Metric Conversion may help students understand how to convert between the different metric units.  I had personally always struggled with metric conversions (probably from lack of interest and from lack of a clear explanation from my teachers when I was young).  This story and technique clicked in my brain and I TOTALLY get it now, as did the kids in the class.  So I had to share.

King Henry's Story

Once upon a time in a faraway land there lived a king who loved chocolate milk. His name was King Henry.

Throughout his kingdom, King Henry made sure that all of the cows were fed great supplies of chocolate to continue to provide him with his beloved chocolate milk drink.

King Henry drank chocolate milk with his breakfast. He drank chocolate milk with his lunch. He drank chocolate milk with his dinner. He even drank chocolate milk for his bedtime snack. King Henry drank chocolate milk by the liters!

King Henry wanted all living creatures in his kingdom to enjoy chocolate milk as much as he enjoyed chocolate milk. However, a liter was not the best serving size for every creature. The Royal Carpenter was called for and the command was given for new serving vessels to be created to fit every creature in the kingdom.

For the creatures smaller than the king, the Royal Carpenter designed deciliters that were 1/10th the size of a liter, centiliters that were 1/100th the size of a liter, and milliliters that were 1/1000th the size of a liter. The milliliters were just right for the Royal Beetles and Bugs of the kingdom.



For the creatures greater than the king, the Royal Carpenter designed dekaliters that were 10 times the size of a liter, hectoliters that were 100 times the size of a liter, and kiloliters that were 1000 times the size of a liter. The kiloliters were just right for the Royal Giants of the kingdom.

The Royal Carpenter lined the vessels up in his workroom from largest to smallest to show the king. The king’s vessel was in the center of the line, for the king was the center of the kingdom. The vessels were arranged in the following order:

kiloliter hectoliter dekaliter liter deciliter centiliter milliliter

King Henry loved the new vessels that were designed larger and smaller than his own for all of the living creatures in his kingdom. The Royal Carpenter explained that the sizes increased and decreased from the king’s liter, the original unit of measurement, by multiples of ten. He explained how to convert between the sizes by multiplying by ten or dividing by ten.

Well, King Henry tragically died not long after that.  The cause of death was very unusual.... he died of drinking way too much chocolate milk.

From then on, all living creatures in the kingdom had no trouble remembering the order of the vessels.  They just thought to themselves:

King Henry Died Unusually Drinking Chocolate Milk

Click HERE to get the story on Google Drive