Teaching the Metric System. Blah! Not exactly my idea of a roaring good time. However, Science class does lend itself to being very hands on. So here begins my two week session of lab after lab after lab in hopes of giving students a concrete visual of the metric system while envoking divergent, cognitive thinking.
First we reviewed how to do conversions when working within a unit (ie: length – meters, volume – liters, and mass – grams). It seems easier to picture the units on a staircase. As you move up the staircase the size increases, and as you move down the size decreases. In order to remember the sequence of the prefixes (added to the base units) a little nuemonic device is helpful. King Henry Doesn’t Usually Drink Chocolate Milk. The first letter of each word represents the first letter of each prefix (kilo, hecto, deka, unit, deci, centi, and milli). Each jump on the staircase equals a jump for the decimal. (Ie: going from deci to kilo means the decimal moves 4 places to the left.)
Conversions Staircase
Calculating mass was first on the agenda. Mass is generally measured in grams (unit) and the tool used to find this a triple beam balance.
3-Beam Balance. Measures Mass.
The day before a lab, I like to define any new vocabulary terms and give students a visual of what they can expect during a lab. I usually have a prepared ppt that I display on my smart board (3M) and give students their own copies. We learn that a 3-beam balance has three beams and three weights. One beam represents the grams in hundreds, another in tens and the third in ones (and decimals). Then after the measurements are taken, you must add up all three beams to get the mass.
Instructions for measuring mass
During the Mass lab, I like to reference a visual on the smart board (3M). Many students will forget the steps for calculation and others find the visual comforting. In this lab students are investigating the question “Which everyday object will have the greatest mass?” Each pair of students is supplied with a baggie filled with regular old, everyday objects. Their mission is to calculate the mass and compare information using a data table. Using a 3-beam balance isn’t as easy as you think.
Everyday Objects
Overall, students really enjoy this lab. They love learning how to use new science tools.
wONEderland 