Introduction to Ratios
1
Warm Up
OBJECTIVE: Students will write real-world quantities as ratios and explain their meaning.
Language Objective: Students will define ratio and will be introduced to ratio language.
.
Write each fraction in simplest form.
3) Which fraction above has the greatest value?
5/9 is bigger than 3/10 because 5/9 is
about 0.55 and 3/10 = 0.3
Agenda
2
Agenda:
OBJECTIVE: Students will write real-world quantities as ratios and explain their meaning.
Language Objective: Students will define ratio and will be introduced to ratio language
1) Warm Up - Individual
2) Lucky Charms Launch – Whole Class
What does the
word quantity
mean?
3) Exploration - Partner
4) Summary - Individual
5) Practice – Small Group
Hint: How
many ears do I
have?
6) Assessment - Individual
A quantity is an
amount of
anything that
we can count.
Like my ears!
3
Lucky Charms Launch
Turn and Talk:
1. Have you ever had Lucky Charms cereal?
2. Are there more marshmallows or oat pieces in a
box of Lucky Charms?
3. Predict how many marshmallows pieces are 1 box.
4. Predict how many oat pieces are in 1 box.
Hint:
4
Agenda
Lucky Charms Launch
Turn and Talk:
1. Have you ever had Lucky Charms cereal?
2. Are there more marshmallows or oat pieces in a
box of Lucky Charms?
3. Predict how many marshmallows pieces are 1 box.
4. Predict how many oat pieces are in 1 box.
Hint: There are almost
2,500 marshmallows and oats
altogether in 1 box.
Agenda
5
Lucky Charms Continued
 There are 287 marshmallow pieces and 2,583 Oat Pieces
in 1 box of Lucky Charms.
We can write this real-world situation as a ratio!
A ratio is a comparison of two different quantities.
We can write a ratio in 3 ways using:
1) a fraction
2) the word, “to”
3) a colon :
Agenda
6
Lucky Charms Continued
Write the ratio of marshmallows to oats in 3 ways.
Let’s try together:
Remember in 1 box:
287 Marshmallows
2,583 Oats
1) A Fraction
2) The Word “to
287 Marshmallows to 2,583 Oats
3) A Colon
287 Marshmallows : 2,583 Oats
Agenda
7
Practice – Work with a partner!
Write a ratio comparing # of people to # of pizzas for each picture.
Picture #1
1 person: 4 pizzas
Picture #2
4 people: 1 pizza
Talk to your partner
 How are the ratios above alike?
 Does the order matter when writing a ratio?
Yes! The situation changes if we change the order of pizza & people.!
Agenda
8
Explore
lions to birds
6 lions to 1 bird
lions : birds
6 lions : 1 bird
Partner Work:
Use the picture above to write a ratio in 3 ways comparing
the # of lions to # of birds.
Agenda
9
Simplifying Ratios
1) Write in simplest form the ratio of Biking to Running.
1 hour of biking
8 hours of biking
=
=
16 hours of basketball 2 hours of basketball
Let’s explain the meaning of this ratio!
This ratio means that for every 1 hour biking, Christian spent ___ hours
playing basketball.
Agenda
10
Simplifying Ratios
2) Write in simplest form the ratio of Christian’s
time spent running to total hours of activities.
Let’s explain the meaning of this ratio!
This ratio means that for every 25 total hours Christian spent on
activities, he spent ____ hours running.
Scaffold
11
Agenda
Summary – Try Independently
1) A ratio is a comparison of two different _________.
2) We can write a ratio in ____ different ways.
3) Ratios can be written as
 As a fraction
 Using the word “to”
Using a colon :
Agenda
13
Practice
Use the CW hand-out to complete the following problems.
Agenda
14
Practice
Use the CW hand-out to complete the following problems.
Agenda
15
Assessment
Complete the following questions on your own!
Write a ratio comparing # of fish to # of sharks in 3 ways.
Agenda
16