Make-up lesson - Unit B, Lesson 10 - Density Triangle
(Standard 8.8.b – students know how to calculate the density of substances)
Use the following directions to complete the lesson in your packet. Directions are in
italics and things to copy are in regular print. Check off each step as you complete it to
make sure you do everything in the lesson. Please ask Mr. Buddy if you have any
questions.
❏ Add the title to the top of the next blank page: Density Triangle
❏ Add the date:
Essential Question
❏ Write down the following essential question:
How does the density triangle work?
Initial Thoughts
❏ Write your answer to the essential question.
Evidence Part I: Density Triangle
❏ Copy
into
the Density Triangle below
your journal.
❏ Write the following steps for using the density triangle into your journal.
1. Cover the variable you are looking for.
2. Write out the equation with the variables that are left.
❏ READ THIS: The density triangle is used to help remember density equations. To use it,
cover the letter of the variable you are trying to figure out.
For example, if you are trying to find the equation for density (D), put your thumb over
the D. The remaining letters show mass/volume (m/v). The equation is D = m/v.
If you are trying to find the equation for mass (m), put your thumb over the m in the
triangle. The remaining letters show density x volume (Dv). The equation is m = Dv.
❏ Use the density triangle to finish the following formulas and write them in your journal:
D=
m=
v=
❏ Write a mnemonic device to help you remember the order of the density triangle (so you
can write it down on tests to help you do density problems). An example would be “Most
Dragons Vomit”; the device uses the same first letters in a phrase.
M
D
V
Evidence Part II: Density Practice
❏ Use the Density Triangle to complete the practice problems on the worksheet. If you do
not have the worksheet, copy the following problems into your journal and complete the
work.
1.
D = 3 g/mL
v = 100 mL
m=?
Example: m = Dv = (3 g/mL)(100 mL) = 300 (g)(mL)/mL = 300g
2.
D=?
v = 95 mL
m = 950 g
Example: D = m/v = (950 g)/(95 mL) = 10 g/mL
3.
D = 5 g/cm3
v=?
m = 20 g
4.
D = 5 g/mL
v = 10 mL
m=?
5.
D=?
6.
D = 5 g/cm3
v = 10 mL
m = 950 g
7.
D = 3 g/mL
v = 10 mL
m=?
9.
D = 1 g/cm3
v=?
m = 20 g
v=?
m = 10 g
8.
D=?
v = 95 mL
m = 95 g
Analysis
❏ Copy down and answer each of the following analysis questions. Remember to use
your evidence section to help you in answering them.
1. Formulate how to solve for each of the following:
D=
m=
v=
2. Explain how to use the density triangle.
3. Predict how you can mess up on a density problem.
Reflection
❏ Draw a venn diagram comparing mass and volume. Use at least 6 points.
Summary
❏ Write a summary of 5-7 sentences about the lesson. Remember to go back to the key
question to help you get started and to use “How to Write a Science Summary” to help
you get ideas about what types of sentences to use.
Big Idea
❏ Copy the following big idea:
The Density Triangle helps you to solve for density, mass, or volume in a density
problem. You cover the part of the triangle you want to find. If the letters are on top of
each other, you divide. If they are next to each other, you multiply.
Vocabulary
❏ Copy the following term and definition into the vocabulary section of your journal. Draw
a picture for each term.
Density Triangle - a trick to help you remember the formulas to solve for density, mass,
or volume in a density problem
Wrap Up
❏ Add this lesson to your Table of Contents.
❏ Add the big idea to your Big Ideas page.