Frequency charts
key notes:
1. Definition of Frequency
- Frequency refers to how often something happens or occurs.
- A frequency chart is a way to organize and display data to show how often each item occurs in a set.
2. Creating a Frequency Chart
- A frequency chart has two main columns:
- Data categories (what you are counting or measuring).
- Frequency (how many times each category occurs).
- Example: If you are counting how many times different colors appear in a set of marbles, your categories might be “Red,” “Blue,” “Green,” and “Yellow.” The frequency will show how many marbles of each color there are.
3. Components of a Frequency Chart
- Categories: The different types or groups you are counting (e.g., colors, shapes, types of animals).
- Tally marks: A quick way to count items. For every 5 items, you group the tally marks in sets of 5 (4 vertical lines and 1 diagonal line).
- Numbers: The final count of each category, written next to the tally marks.
4. Example of a Simple Frequency Chart
Learn with an example
1) Several children compared how many thank-you notes they had written during the previous month.
| Writing thank-you notes | |
| Thank-you notes written | Frequency |
| 0 | 7 |
| 1 | 15 |
| 2 | 14 |
| 3 | 9 |
| 4 | 3 |
How many children wrote at least 1 thank-you note?____
- Find the rows for 1, 2, 3, and 4 thank-you notes. Add the frequencies for these rows.
- Add: 15 + 14 + 9 + 3 = 41
- 41 children wrote at least 1 thank-you note.
2) The primary school art teacher wrote down how many flower pots each child painted last week.
| Painting flower pots | |
| Flower pots painted | Frequency |
| 0 | 16 |
| 1 | 9 |
| 2 | 7 |
| 3 | 20 |
How many children painted exactly 1 flower pot?____
- Find the row for 1 flower pot and read the frequency. The frequency is 9.
- 9 children painted exactly 1 flower pot.
3) Students at Georgetown Secondary School wrote and submitted poems for a district-wide writing contest.
| Writing poems | |
| Poems written | Frequency |
| 1 | 3 |
| 2 | 9 |
| 3 | 16 |
| 4 | 7 |
| 5 | 4 |
How many students wrote fewer than 4 poems?______
- Find the rows for 1, 2, and 3 poems. Add the frequencies for these rows.
- Add: 3 + 9 + 16 = 28
- 28 students wrote fewer than 4 poems.
Let’s practice!🖊️
