Science Skills: Measuring (density)
Overview: Working by yourself you will find the density of at least 2 rectangular solids and 2
irregularly shaped objects.
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All numbers require units—in the data table and in the calculations
NO naked numbers.
When measuring a rectangular solid there is no hard and fast rule as to which side is height,
length or width. Make a decision for you for these objects and use that decision for all the
objects you are measuring. Measure each dimension to nearest centimeter (cm)
Calculations for all 4 objects need to be shown (see samples on the other side).
Rounding Remember when rounding you need to look at the number to the right of the place
value of that has the desired accuracy. When rounding to the nearest tenth, look at the number
in the hundredth’s place (the number to the right). If that number is 0-4 round down; if that
number is 5-9 round up.
Ex A: 0.678
hundredth
place
tenth
place
0.678 rounds to 0.7 because the 7 in the hundredths place is between 5-9
so the 6 in the tenth’s place is changed to a 7.
thousandth
place
Ex B: 0.138
0.138 rounds to 0.1 because the 3 in the hundredth place is between 0-4
so the 1 in the tenth’s place is changed to a 1
Materials at each station:
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metric ruler
graduated cylinder
scale with weight boat—shared between both sides of the bench
rectangular solids made of different materials—shared between both sides of the bench
irregularly shaped objects – keep each side’s objects in own bowl
o Irregularly shaped objects’ volume can’t be easily measured by conventional methods
(like by finding the objects’ height, length, width, etc.).
Materials you brought to the station:
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NB—have the information from the whiteboard copied into your notebook
pencil and calculator (phone OK)
2 Data Tables
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use the following column headings to set up your data tables
the number of rows depend on how many objects you end up measuring
do all measurements before doing calculation
turn over for procedure
Procedure for Rectangular Solids
Procedure for Irregular Objects
1. Mass the object – don’t forget the units,
fill in correct column/row in your data
table
1. Mass the object – don’t forget the units, fill in
correct column/row in your data table
Pay attention to the note taped to the scale.
2. Measure each side to nearest
centimeter—decide yourself which
dimension will be height, width and
length—and use that decision for all of
the rectangular solids.
2. Fill graduated cylinder with more than 15 mL
of water. Note amount of water in the “initial
water volume” column. Water should be
measured to the nearest tenth of a mL
(19.5mL for example)
3. Repeat steps 1-2 with additional objects
3. Add the object to the graduated cylinder.
4. Read the graduated cylinder (to nearest
tenth). Note amount of water in the “final
water volume” column in the data table.
5. Repeat steps 1-4 with additional object(s)
Clean UP: both sides need to be dry, all objects should be dry and put back into correct
bowls—look at list on bowl. The station needs to be reset for the next group of students.
Can go back to your table if you want to do the calculations there
Calculations
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For each object you need to show your calculations
Remember to round density (final answer) to the nearest tenth.
Copy the three equations below
Sample calculations for each type of solid.
Must these same calculations for EACH object. Underline final density
Round density to the nearest tenth (0.1)
Equations
regular volume = height x length x width (units cm3)
density =
𝑚𝑎𝑠𝑠
𝑣𝑜𝑙𝑢𝑚𝑒
(units g/cm3 or g/mL)
irregular volume = final volume – initial volume (units in g/mL)
Examples of how to show your work correctly
gray block
volume =
density =
marble
12.1cm x 3.4cm x 19.7cm
85.4 𝑔
804.458 𝑐𝑚3
= 0.1061
𝑔
𝑐𝑚3
= 804.458 cm3
= 0.10
𝑔
𝑐𝑚3
don’t have to round
do have to round
volume = 18.1 mL -- 14.9 mL = 3.2mL
density =
12.6 𝑔
3.2 𝑚𝐿
= 3.937
𝑔
𝑚𝐿
= 4.0
𝑔
𝑚𝐿
calculator
value
final value that
has been correctly
rounded
The final lab report should have three sections: notes/information (from the board), data tables,
equations and calculations.