Data Representation
Data Handling · Data Representation
CBC Grade 5 Mathematics — Data Representation
Lesson objectives
By the end of this topic, a learner should be able to:
- Collect data relating to a real-life situation
- Record collected data in a table
- Use tally marks to count data
- Prepare and interpret a frequency table
Data Representation
Data is information you collect to answer a question. On its own it is just a pile of answers. Organised, it tells you something.
a) Asking a good question
Start with a question you can actually answer by counting.
"Which fruit do learners like best?" works. You can ask everyone and count.
"Is fruit nice?" does not work. There is nothing to count.
b) Collecting the data
Decide who you will ask. Your class, your group, or your family.
Ask each person once. Ask everyone the same question, in the same words.
Write each answer down as you get it. Do not try to remember them.
c) Tally marks
Tally marks are a quick way of counting as you go.
Draw one short line for each answer.
When you reach the fifth, draw it across the other four. That makes a group of five.
Groups of five are easy to count. Counting in fives is much faster than counting single lines, and you make fewer mistakes.
d) A frequency table
Frequency means how many times something happened.
| Fruit | Tally | Frequency |
|---|---|---|
| Mango | IIII III | 8 |
| Banana | IIII I | 6 |
| Orange | IIII | 4 |
| Pawpaw | II | 2 |
Put each answer in its own row.
Count the tallies and write the number in the frequency column.
Add the frequency column at the end. Here it comes to 20, which should match the number of people you asked. If it does not, count again.
e) Reading the table
The biggest frequency is the most popular. Here that is mango, with 8.
The smallest is the least popular. Here that is pawpaw, with 2.
To compare two rows, subtract the smaller from the larger. Mango beats orange by 4.
f) Showing it as a picture
A picture makes the answer clear at a glance.
The taller the bar, the more learners chose that fruit.
g) Where this is used
A teacher counts who is present. A shopkeeper sees what sells best. A health worker counts visits. A farmer records rainfall each week.
:::checkpoint Check yourself
- What does frequency mean?
- How do you show the fifth tally mark?
- Why should you add up the frequency column?
- In the table above, how many more learners chose mango than pawpaw? :::
Definitions
- Data — information collected, often through observation or asking questions.
- Tally marks — counting in groups of five, using strokes.
- Frequency — how many times something occurs in a set of data.
- Frequency table — a table summarising data by category and frequency.
Must remember
- Every fifth tally mark crosses the previous four.
- Always check frequencies add up to the total items collected.
- A frequency table needs a clear category column and frequency column.
- Interpreting means answering real questions from the table.
Conclusion
Collecting, tallying, organising, and interpreting all build toward turning raw information into something clear enough to answer questions from.
Bridge to practice
The exercises ask you to tally, build a frequency table and read it. Always check your frequencies add up to the number of people asked.