Fill a jar with your favorite candy and have students guess the number of grams of candy that are in the jar. Give students one clue: 453 grams equals approximately one pound of candy. A fun twist: Fill the jar with licorice and ask students how long, in centimeters, it would be if they were to line the licorice up from end to end. Give the hint that a centimeter is approximately the width of a pinky finger.
2. Prefix Mnemonics
The secret to success with the metric system is learning the prefixes. Whether exploring measurements of length, mass, or capacity, the prefixes are the same (kilo, hecto, deka, meter, deci, centi, milli). The following phrase is an excellent way to remember the prefixes and their order: “King Henry Drinks Many Delicious Chocolate Milkshakes.” What other phrases can students devise?
3. Metric Body
Ask students to measure in centimeters (1) around their heads, (2) around their necks, (3) their arms from their shoulders to their fingertips, and (4) from their elbows to their wrists. Next have them find their heights and their spans, as well as the lengths of their feet and their paces. Ring size, length of index finger, and width of thumbnail can also be included. Then make comparisons. What is the ratio of their heights to the distance around their heads? (Usually around three.) Were any measurements similar? (Distance from elbow to wrist and length of foot.) Determine whether students are squares (height = span), tall rectangles (height > span), or wide rectangles (span > height).
4. Metric Measurement Hunt
Invite students to work with a partner to find items in the classroom with specific metric lengths, such as 45 cm, 1.5 m, and 6 mm. Have them record the object, the actual length, and the difference between the estimated and actual length. Discuss the objects found and the accuracy of students’ guesses.
5. Metric Olympics
This activity comes from the AIMS Educational Foundation. Here are some stations to try:
• Paper Straw Javelin Throw: Place your feet on the starting line and throw the “javelin” (a paper straw). Measure and record the distance, in centimeters, from the starting line to where the javelin lands. You can also do a “discus” throw using a paper plate and a “shot put” throw using a cotton ball.
• Sponge Squeeze: Soak sponges in a bucket. Students squeeze the sponge into a liter container and measure the capacity of the water squeezed.
• Marble Grab: Invite students to grab a handful of marbles and place them on a scale, measuring the marbles’ weight in grams.
• Award Ceremony: Award students with the farthest throwing distances, most water squeezed, or the largest mass of marbles. Or, as the AIMS Foundation suggests, have students estimate each event and the student with the lowest differences between their estimates and their actual measures wins.