Last Name____________________First Name_______________Period_____Date___________
Metric Measurement – Mass
INTRODUCTION: How can you figure out how much of your pencil gets “eaten” by a pencil
sharpener each time you sharpen a pencil? How can you figure out how much a gulp of water
is?
OBJECTIVE: In this activity, we will become familiar with the parts of a triple-beam balance
that is used to measure mass, and we will practice measuring the mass of different objects.
Following this, we will learn how to “weigh-by-difference” to find the mass of different
objects.
To Weigh Objects
1. Use the following steps to weigh each object listed in the chart (in grams), and record its
mass in the chart on the back.
2. Make sure the weigh pan is clean. Look at the chart on the back for the objects to measure.
3. Place an object on the weigh pan. The pointer line should move up. Your goal is to get the
pointer line even with the 0 marked on the post.
4. To do this…
a. Move the largest weight (100 g) on the middle bar to the right landing in each notch.
If you get to the 500g mark and the pointer line has not moved below the 0, move the weight
all the way back to zero and go to the middle-sized weight (10 g) on the last bar.
b. If you land on a notch and the pointer line goes below 0, move the weight back a
notch and leave the weight there. Move to the middle-sized weight on the last bar.
c. Move the middle-sized weight (10 g) in the back to the right landing in each notch.
If you get to the 100 g mark and the pointer line has not moved below the 0, move the weight
all the way back to zero and go to the smallest weight (.1mg) on the front bar.
d. If you land on a notch and the pointer line goes below 0, move the weight back a
notch and leave the weight there. Move to the smallest weight (.1mg) on the front bar.
e. Slide the smallest weight (.1 g) to the right until the pointer moves to 0. If you get to
the 10g mark and the pointer line has not moved, slide the weight back to zero. If the pointer
begins to move, slide the weight until the pointer line is at 0 and stop. The numbers are the
grams and the small lines are the tenths of grams.
5. Add together all of the numbers that your weights are on. This is the mass of your object in
grams. Record the mass with correct units in the chart on the back.
©Mark Twain Media, Inc., Publishers
Last Name____________________First Name_______________Period_____Date___________
Object
Mass
Show the units!
Rock
Small paper
clip
Two large
paper clips
Clay
One nickel
One quarter
To Weigh Objects by Difference
When doing this, we will be weighing an object, removing from or adding to the object, and
then reweighing the object to see how much mass was taken away or added.
Object
Mass After Change
Mass Before
Mass Change (done at
the end of the lab)
1. Empty Graduated
Cylinder
2. Empty Cup
1. Weigh the empty cylinder. Write the mass in the column under “Mass Before.” (This is the second
column!) Add exactly 100 mL of water to the cylinder. Reweigh the mass and fill in the column under
“Mass After Change.” (This is the first column!) Wait to calculate change.
2. Weigh an empty cup. Write the mass in the column under “Mass Before.” Add the candy to the empty
cup. Reweigh the mass and fill in the column under “Mass After Change.” Pour your candy onto a clean
paper towel. Wait to calculate change. Do not eat your candy.
4. Split your candy to share with each other. Clean up your station so that it looks like it did when you
started. Sit down to complete the rest.
5. For every object subtract the “Mass Before” from the “Mass After Change” and write that mass under the
“Mass Change” column. The “Mass Change” is the mass of the objects below. Fill in the objects’ masses.
Questions:
What is the mass of 100 mL of water? ____________________
What is the mass of the candy? ____________________ (Eat your candy!)
©Mark Twain Media, Inc., Publishers