Introduction
GOOD DAY GRADE 11’s.
In today’s lesson we will be focusing on probability. We will consider the following:
- Calculating probability
- ways to calculate the number of outcomes.
- kinds of events as well as replacing or not replacing.
Click on the link(s) below to learn more in depth about probability, ways to calculate the number of outcomes, kinds of events as well as replacing or not replacing
NB: In probability when you deals with objects and things a decimal answer is allowed, you round of to the nearest whole number when instructed.
- When you deal with humans, animals and objects (Houses, sweets, fruits), you round off to the nearest whole number . The round of from 5 rule is not applicable e.g 42,3 you round it up to 43.
Task
When doing probability calculations, the possible ways in which the calculation could work are called the outcomes.
• The specific outcome that you are looking for is called an event.
Step 1
- Probability = Divide the number of events by the number of possible outcome.
Step 2
- Probability can be expressed in decimals or percentages. If your answer is required to be in a decimal form , you round off to the nearest decimal place e.g 23,345 round off to 23,35.
- If your answer is required to be in a percentage form = Divide the number of events by the number of possible outcome x 100 .
Step 3
You conclude by expressing your answer in words and numbers
Step 4
All answers in percentage form must add up to 100%.
Example:
In a class of 34 learners, there are 10 learners who identify themselves as christians, 20 learners as Muslims and 4 as atheists. Calculate the % probability that you will find
a) Christian learners
Solution= Number of Christian learners/ Total number of Learners in class .
= 10/34 = 0.2941176471
=0.2941176471 x100
= 29.4117
=29.41 %
OR
Total number of Christian learners/ Total Number of learners in class multiply by 100
10/34 x 100 = 29.4117
= 29.41%
therefore 29.42% of the class identifies themselves as Christians
b) Muslim learners
Total number of Muslim learners/ Total Number of learners in class
= 20/34 = 0.5882352942
= 0.5882352941 x 100
= 58. 8235
= 58.82%
therefore 58.82% of the class identifies themselves as Muslims.
OR
Total number of Muslim learners/ Total Number of learners in class multiply by 100
20/34 x 100 = 58.82%
c) Atheists
Total number of Atheist learners/ Total Number of learners in class
4/34 = 0.1176470588
0.1176470588 x100 = 11.7647
= 11.765 = 11.77%
therefore 11.77% of the classroom identifies themselves as atheists.
Process
A local NGO wants to give back to Grade 10 Langs high school girl leaners by giving each learner a free sanitary towel pack. When the NGO contacted the school, they were told that 58,8% of the learners in Grade 10 at the school were boys. In order for the NGO to be able to determined how many packs must they bring at the school, they need to know how many girl leaners are they in grade 10 at Langa High School.
Question 1
Calculate the % number of girls in Grade 10 at Langa High School.
Question 2
Calculate the total number of girls in grade 10 at Langa High school.
Question 3
How many packets of sanitary towels should the NGO bring for the girls in grade 10.
Evaluation
SOLUTIONS
Question 1
Total % no of girls
= Total % no of Grade 10 - Total % no of boys
= 100% - 58.8%
= 41.2 %
therefore the % number of girls in grade 10 at Langa High School is 41.2%
Question 2
Total number of girls
= % number of girls/ Total grade 10 % then multiply by 100
= 41.2%/ 100 x100 =41.2
= Round of to the neares whole number
42
therefore the total number of girls in grade 10 at Langa High School is 42.
Question 3
The NGO company must bring 42 packets of sanitary towels in order for each leaner to receive a packet.
| Q1 | 2 |
| Q2 | 3 |
| Q3 | 2 |
Total marks - 7 marks
Conclusion
ZOnce you have completed the exercise, have watched the videos and went through the notes provided you should have the basics and an is a of what is probability, how it is calculated and expressed.
You should have acquired skills to deal with basic probability whether be it in a Mathematical Literacy classroom setting or in real life , the skill is applicable.
This lesson was a s basic foundation on probability. For more understanding on probability click on the link below and watch the video to prepare for our next class .
Teacher Page
In this ever-changing world, I chose to teach this lesson to provide some basic fundamental insight on data handling in Mathematical literacy, allowing learners to become acquainted with working with probability problems and solutions .
This will serve as a foundation and will be expanded upon in due course while remaining consistent with the curriculum.
This also serves as an invitation to my fellow colleges to seize the opportunity to engage in e-learning, given how beneficial, user-friendly, and effective WebQuest is.
Thank you very much.
Lihle Bhayibhile