Lesson Notes By Weeks and Term v5 - Grade 2

Lesson Video

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Performance objectives

• Collect data using simple surveys.
• Organise data with tally marks and tables.
• Show data using pictographs and bar graphs.
• Answer questions about the data.
• Practice addition and subtraction using our data.

Lesson summary

Data handling is an important skill that helps us organise and understand information all around us. In South Africa, we use data every day – from figuring out which fruits are the most popular at the market to understanding how many learners are in our class. By learning how to collect, sort, and represent data, we can make better decisions and understand the world around us better. This week's focus is on revising previously learned concepts and applying them to new data sets. We will use pictographs and simple bar graphs to display our findings. This will help us in future when dealing with more complex data.

Lesson notes

2.1 Data Collection: Data is information that we gather. We can collect data by asking questions (conducting surveys), observing, or counting. A survey is a set of questions we ask to find out what people think or like.

Example: Let's say we want to know which fruit is the most popular in our class. We can ask each learner to tell us their favorite fruit. This is a survey! 2.2 Tally Marks and Tables: Tally marks are a way to quickly count things. We use vertical lines (||||) and then cross them over for every fifth item (||||). A table helps us organise the tally marks and the total count for each item.

Example: | Fruit | Tally Marks | Count | | ------ | ----------- | ----- | | Apple | |||| | 4 | | Banana | |||| | | 6 | | Orange | || | 2 | 2.3 Pictographs: A pictograph uses pictures or symbols to represent data. Each picture stands for a certain number of items. It's important to have a key that tells us what each picture represents.

Example: Let's use a smiling face to represent one fruit. | Fruit | Pictograph | | ------ | ------------------------------------------ | | Apple | 😃😃😃😃 | | Banana | 😃😃😃😃😃😃 | | Orange | 😃😃 | Key: 😃 = 1 fruit 2.4 Bar Graphs: A bar graph uses bars of different lengths to represent data. The length of the bar shows the number of items.

The graph has two axes: a horizontal axis (x-axis) that lists the categories (e.g., fruits) and a vertical axis (y-axis) that shows the number of items.

Example: Using the fruit data from above: ``` 6| 5| B 4| A B 3| A B 2| A O B 1| A O B 0| A O B ----- A O B pple ranga nana ``` Explanation of the Bar Graph: The y-axis represents the number of fruits (0 to 6). The x-axis represents the type of fruit (Apple, Orange, Banana). The height of the bar for each fruit shows how many learners chose that fruit. 2.5 Revision of Addition and Subtraction: We can use the data we collect to practice addition and subtraction.

Example: How many learners like apples and oranges in total? (4 + 2 = 6) How many more learners like bananas than apples? (6 - 4 = 2) 2.6 Why it Matters: Data handling is all around us!

Consider: Stocking a Tuckshop:* A school tuckshop can track the sales of snacks and drinks to see which items are most popular and ensure they have enough of those items in stock. This reduces waste and maximizes profit - good business sense.

Weather Reports:* When the weather service collects data, they use it to make weather reports that help farmers make decisions about planting and harvesting. This impacts food security.

Traffic Analysis:* Cities analyze traffic data to plan roads and public transportation routes to alleviate congestion. Guided Practice (With Solutions)

Question 1: The Grade 2 class collected data on their favorite pets.

Here are the results: Dogs: 8 Cats: 5 Birds: 3 Represent this data using tally marks and a table.

Solution: | Pet | Tally Marks | Count | | ------ | ----------- | ----- | | Dogs | |||| |||| | 8 | | Cats | |||| | | 5 | | Birds | ||| | 3 |

Commentary: We used tally marks to easily count the number of learners who liked each pet. Each group of five tally marks is crossed out for quicker counting.

Question 2: Using the same data as Question 1, create a pictograph. Use a heart (♥) to represent one pet.

Solution: | Pet | Pictograph | | ------ | ------------------------------------- | | Dogs | ♥♥♥♥♥♥♥♥ | | Cats | ♥♥♥♥♥ | | Birds | ♥♥♥ | Key: ♥ = 1 pet

Commentary: We chose a heart as our symbol. We drew the correct number of hearts for each pet according to the data.

Question 3: Using the same data as Question 1, create a simple bar graph.

Solution: ``` 8|D 7|D 6|D 5|D C 4|D C 3|D C B 2|D C B 1|D C B 0|D C B ------- DCB ogs ats irds ```

Commentary: We labeled the x-axis with the names of the pets (Dogs, Cats, Birds) and the y-axis with the number of learners (0 to 8). The height of each bar matches the number of learners who chose that pet.

Question 4: Looking at the bar graph you created in Question 3, which pet is the most popular? How many learners like that pet?

Solution: Dogs are the most popular pet. 8 learners like dogs.

Commentary: The bar for dogs is the tallest, meaning the most learners like dogs. The height of the bar tells us the number of learners (8). Independent Practice (Questions Only)

Question 1: A class of Grade 2 learners were asked about their favourite colour.

The results were: Red - 7 learners, Blue - 9 learners, Green - 5 learners, Yellow - 3 learners. Create a table to show this data.

Question 2: Using the information from Question 1, draw a pictograph representing the number of learners who favour each colour. Use a star (☆) to represent 1 learner.

Question 3: Now, draw a bar graph to represent the same information from Question

1. Remember to label your axes!

Question 4: Using your bar graph from Question 3, answer the following questions: Which colour is the most popular? Which colour is the least popular? How many more learners like blue than green?