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Selecting an
Appropriate Representation of a Problem- what does that mean anyway?
It means,
given certain facts and numbers, how can you organize them to
make the most sense?
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Let's see an example! |
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In your mom's exercise class,
there are six people under 40, and four people 40 and over. |
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Let's see what
problems could be answered from this problem: |
| 1. What is the ratio of forty
and over to under forty? |
2. What is the
total number of people in the class? |
| 3. What is the ratio of under
forty to the total number of people in the class? |
4. What is the ratio of people
forty and over to the total number of people in the class? |
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So
ratios and
proportions are
good ways to represent data in word problems. |
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Let's see another example! |
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In your class of 23 there are
5 kids that are left handed. How many students are right
handed? |
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Let's see how we
can use this information to represent a problem.
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Set up an equation.
Let y = number of right handed students in class |
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5 + y = 23
5 - 5 + y = 23 - 5
y = 18 |
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So
equations with
variables are good ways to represent data in word problems. |
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One more
example - one with an inequality! |
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Meg
has run 2.5 miles today, and she ran 5.4 miles yesterday.
She needs to run at least 10 miles every two days to train for a
marathon. Has she reached her goal yet? |
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Let's see how we
can use this information to represent a problem.
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You are comparing a sum to a
total. |
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2.5
+ 5.4 is greater or less than 10
2.5 + 5.4 < or > 10
7.9 < 10
therefore Meg has NOT reached her goal yet. |
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So
inequalities are
good ways to represent data in word problems. |
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There are many ways to
represent problems, among them are equations,
inequalities, and ratios. |
Ready for
Practice? or a
Matching Game?
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