Skip to main content
guest
Join

Help

Sign In
percentagesactivity
Home
guest

Join

Help

Sign In
percentagesactivity
Wiki Home
Projects
Recent Changes
Pages and Files
Members
Navigation menu
Home
Getting started
Percentages
What does percent mean? (TASK 1)
Decimals, fractions and percentages
Understanding percentage questions
Dual number lines  introduction
Dual number lines  missing part
Dual number lines  missing whole
Percentage wheel
Percentage activities (TASK 2)
Percentages in real life (TASK 3)
Real life percentage questions (TASK 4)
Group project (TASKS 57)
Assignment information
Task 1
Image example
How to create your image
Upload your image here
Task 2
Question example
Upload your percentage question here
Task 3
Research page  percentages in real life
Task 4
Real life question example
Upload your real life percentage question here
Task 5
Video task
Video topic ideas
Video example
How to upload your video
Task 6
Worksheet task
Worksheet example
Task 7
Answer key example
Assessment Rubric
Team home pages
Projects
Project example
Class discussion board
Resources
How to use Cam studio
Storyboard template
Wikispaces tutorials
Dual number line  missing part
Edit
0
5
…
0
Tags
No tags
Notify
RSS
Backlinks
Source
Print
Export (PDF)
Missing part problems
There are 60 students in Grade 7 and 20% play football. How many students play football?
Solution 1. Unitary method – finding 1% first
Step 1: Draw the dual number line
Step 2: Find 1%
Step 3: Find 20%
Dual number line: 20% = ? of 60
Dual number line: find 1% of 60
Dual number line: Find 20% of 60
There are 60 students and 20% play football.
How many students play football?
1% is 0.6 students
20% is 20 × 0.6 = 12
There are 12 students who play football
NOTE:
A variation, particularly useful in this case, is to find 10% first and then find 20%.
Solution 2. Noticing 100 = 5 × 20
Step 1: Draw the dual number line
Step 2: Notice link between percents
Step 3: Use link on quantities
Dual number line: 20% = ? of 60
Dual number line: One fifth of 100% = 20%
Dual number line: One fifth of 60 is 12
One fifth of 100% is 20%
One fifth of 60 is 12
There are 12 students
who play football
Solution 3. Using the ratio between 100 and 60
Step 1: Draw the dual number line
Step 2: Notice link from percent to quantity
Step 3: Use link from percent to quantity
Dual number line: 20% = ? of 60
Dual number line: 6/10 of 100 = 60
Dual number line: 6/10 of 20 = 12
There are 60 students and 20% are play football. How many students play football?
60% of 100 = 60
6/10 of 20 = 12
There are 12 students who play football
Solution 4. Identifying equivalent proportions
Step 1: Draw the dual number line
Step 2: State that both sides ofthe line are in the same proportion
Step 3: Solve algebraically
Dual number line: 20% = ? of 60
Dual number line: 20/100 = x/60
Dual number line: 20/100 = x/60
There are 60 students, and 20% play football. How many
students play football?
20/100 = x/60
20/100 = x/60
There are 12 students who play football
Now go to
Dual number lines  missing whole problems
Source:
http://www.education.vic.gov.au/studentlearning/teachingresources/maths/mathscontinuum/number/N55003P.htm
Javascript Required
You need to enable Javascript in your browser to edit pages.
help on how to format text
Turn off "Getting Started"
Home
...
Loading...
There are 60 students in Grade 7 and 20% play football. How many students play football?
How many students play football?
There are 12 students who play football
There are 12 students
who play football
There are 12 students who play football
students play football?
There are 12 students who play football
Dual number lines  missing whole problems
http://www.education.vic.gov.au/studentlearning/teachingresources/maths/mathscontinuum/number/N55003P.htm