October 22, 2014
October 23, 2014
1- Get your folder and a calculator
2- Get out White Board Materials
3- Review of solving proportions
4- Brain pop video and quiz
October 22, 2014
Solving Proportions
October 22, 2014
Solving Proportions
Learn to solve proportions by using cross
products.
Vocabulary
Cross Product:
For two ratios, the product of the numerator in one ratio
and the denominator in the other is a cross product. If
the cross products of the ratios are equal, then the
ratios form a proportion.
October 22, 2014
If the cross products of the ratios are equal, then the
ratios form a proportion.
October 22, 2014
You can use the cross product rule
to solve proportions with variables.
1= 4
2 8
October 22, 2014
Example 1: Solving Proportions
Using Cross Products
Use cross products to solve the proportion.
Cross Multiply.
Divide by 15 to find the answer
to m.
October 22, 2014
Check It Out: Example 1
Use cross products to solve the proportion.
October 22, 2014
5.5 Solving Proportions
Problem Solving
October 22, 2014
Example 2: Problem Solving Application
If 3 volumes of Jennifer’s
encyclopedia takes up 4 inches
of space on her shelf, how
much space will she need for
all 26 volumes?
volumes
inches
Set up a proportion using the
given information. Let x represent
the inches of space needed.
=
She needs
inches for all 26 volumes.
October 22, 2014
Check It Out: Example 2
John filled his new radiator
with 6 pints of coolant, which is
the 10 inch mark. How many
pints of coolant would be
needed to fill the radiator to
the 25 inch level?
=
October 22, 2014
Lesson Quiz: Part I
Use cross products to solve the proportion.
t=
x=
r=
n=
October 22, 2014
Lesson Quiz: Part II
hint: pounds
$
October 22, 2014
Chromebooks
1- log on to you math text book.
2- Chapter 1 lesson 6 - resources tab
3- Brain pop video and questions
This is similar to a PARCC assessment.
October 22, 2014