ratio and percent note.notebook
February 20, 2014
Unit 6:
Ratios and
Percent
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ratio and percent note.notebook
February 20, 2014
Unit 6: Ratios and Percent
After completing this unit, you should be able to:
• Demonstrate an understanding of ratio, concretely, pictorially and symbolically.
Provide a concrete or pictorial representation for a given ratio.
‐
Explain the part/whole and part/part ratios of a set; e.g., for a group of ‐
3 girls and 5 boys, explain the ratios 3:5, 3:8 and 5:8.
‐ Write a ratio from a given concrete or pictorial representation.
‐ Express a given ratio in multiple forms, such as 3:5, or 3 to 5.
‐ Identify and describe ratios from real‐life contexts, and record them symbolically.
‐ Demonstrate an understanding of equivalent ratios.
‐ Solve a given problem involving ratio.
• Demonstrate an understanding of percent (limited to whole numbers), concretely, pictorially and symbolically.
‐ Explain that “percent” means “out of 100.”
‐ Explain that percent is a ratio out of 100.
‐ Use concrete materials and pictorial representations to illustrate a given percent.
‐ Record the percent displayed in a given concrete or pictorial representation.
‐ Identify and describe percents from real‐life contexts, and record them symbolically.
‐ Express a given percent as a fraction and a decimal.
‐ Solve a given problem involving percents.
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ratio and percent note.notebook
February 20, 2014
Part 1: Ratios
A ratio is a comparison of any two quantities. Ratios may be part‐to‐part or part‐to‐whole.
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ratio and percent note.notebook
February 20, 2014
Learn Alberta Math 6 Spy Guys
Click here!
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ratio and percent note.notebook
February 20, 2014
Using the given shapes, create the following ratios:
(a)
3:1
part-to-part
(b)
4:6
part-to-whole
Create your own ratio and model it using these shapes.
Indicate if the ratio is part-to-part or part-to-whole and
explain why your set is part-to-part or part-to-whole.
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ratio and percent note.notebook
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ratio and percent note.notebook
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ratio and percent note.notebook
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Math Station Day!
Station 1: Create a poster on ratios found in the classroom. Classify the ratio as part‐to‐part or part‐to‐whole.
Examples: boys:girls
students:desks
Station 2: Explore the ratios of the different colors in a set of pattern blocks. Record your ratios on posters by writing the ratio, drawing a picture of your ratio, and classifying it as part‐to‐
part or part‐to‐whole. Station 3: Whiteboards. Partner up and ask each pair to give the other partner a ratio and have them model it. Classify the ratios as part‐to‐part or part‐to‐whole and explain why.
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ratio and percent note.notebook
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Equivalent Ratios
3:2 (part-to-part)
We can create an equivalent ratio by
replicating the original model.
Equivalent ratio =
6:4 (part-to-part)
By continuing to replicate your original model, you can
create additional equivalent ratios.
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ratio and percent note.notebook
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Now it's your turn to create equivalent ratios!
Create two equivalent ratios for the following
part-to-part ratio
2:6
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ratio and percent note.notebook
February 20, 2014
Now it's your turn to create equivalent ratios!
Create two equivalent ratios for the following
part-to-whole ratio
1:4
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ratio and percent note.notebook
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Now it's your turn to create equivalent ratios!
Step 1: Create a set and write a ratio found in this set.
Indicate if it is a part-to-part or part-to-whole ratio.
Step 2: Exchange ratios with partner and have them
create two equivalent ratios plus models for your original
ratio.
Step 3: Correct your partner's equivalent ratios. Did they
create correct equivalent ratios? If not, explain to your
partner what they need to do to create an equivalent
ratio.
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ratio and percent note.notebook
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Exit Activity
(1) Create five ratios that are equivalent to 1:3
(2) In a class of 30 students, there are 20 girls. Explain why the ratio of boys to girls is 1:2.
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ratio and percent note.notebook
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Real World Connections: Ratios
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Ratio Problem Solving
Donald’s fruit punch recipe calls for 3 L of ginger ale, 1 L of strawberry juice and 2 L of orange juice. If Donald uses 9 L of ginger ale, how much strawberry juice and orange juice should he use? Justify your answer.
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Possible Strategies
Show your
work!!!
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ratio and percent note.notebook
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Part 2: Percent
• Percent is a ratio and, therefore, another name for a fraction. • Percent can be viewed as a part‐to‐whole ratio that compares a number to a whole divided into 100 equal parts. • Note the connection to the word “cent” where a cent is 1/100 of a dollar. 19
ratio and percent note.notebook
February 20, 2014
Learn Alberta Math 6 Spy Guys
Click here for the video!
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ratio and percent note.notebook
February 20, 2014
You can use a hundredths grid to represent percents by shading in the desired portion of the grid. For example, to represent and model 25%, you could use a hundredths grid to shade 25 blocks out of 100.
Percent:
Ratio (Part-to-whole):
Fraction:
Percent:
Ratio (Part-to-whole):
Fraction:
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Activity: Hundredths Grid
On a blank hundredths grid, use the following instructions
to shade in the grid.
Shade 30 blocks red, 20 blocks blue, 45 black and 5 yellow.
Describe each color using a fraction, percent and a part to
whole ratio.
Colour
Number of Fraction
blocks coloured
Red
30
Blue
20
Black
45
Yellow
5
Percent
Part­to­whole ratio
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ratio and percent note.notebook
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You should be able to fluently move between naming a number as a fraction, ratio, percent, and decimal. For example, when given a hundredths grid like the one below,
you should see this as:
‐ 25% (Percent)
‐ 25 100 (Fraction)
‐ 25:100 (Part‐to‐whole ratio)
‐ 0.25 (Decimal)
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