Chapter 14: Data Handling
How many friends like mango? Who has the most pets? Numbers can answer these too , once we collect, sort and see them as pictures.
What we'll learn
- Collect and sort data.
- Use tally marks to count quickly.
- Read and draw pictographs and bar graphs.
- Compare and answer questions from data.
The big idea
Data is just information collected , like a list of favourite colours or daily temperatures. Raw data is messy. We organise it into a table.
Tally marks are quick counting strokes. Four upright lines |||| and the fifth one across them makes a bundle of 5. So |||| means 5. Two bundles plus 3 more = 13.
A pictograph shows data with little pictures. Each picture stands for a fixed number , say, one mango = 5 mangoes sold.
A bar graph uses tall rectangles. The taller the bar, the bigger the number. Bars sit on a base line, and each bar is for one category.
Once a graph is drawn, anyone can quickly compare. "Which fruit is liked most?" Look for the tallest bar. "How many like banana?" Read the height of the banana bar.
Explore with examples
1. Tally marks for 8: how?
|||| ||| , one bundle of 5 plus 3 more = 8.
2. A class has 12 mango, 8 banana, 6 apple, 4 grape lovers. Draw a tally.
| Fruit | Tally | Count |
|---|---|---|
| Mango | |||| |||| || | 12 |
| Banana | |||| ||| | 8 |
| Apple | |||| | | 6 |
| Grape | |||| | 4 |
3. From the above table, which fruit is most liked?
Mango , the count is the highest (12).
4. A pictograph shows 1 cycle = 4 children. If 5 cycles appear, how many children?
5 × 4 = 20 children.
Hands-on activities
Class Survey
Ask 20 friends their favourite ice cream flavour. Note answers using tally marks. Make a table. Find the most popular flavour.
Weather Watch
For 7 days, note daily weather as Sunny, Cloudy, or Rainy. Make a tally chart. At the end, count each.
Bar Builder
Use coloured paper strips. Cut their length based on the data , longest strip for highest count. Stick them side by side. Behold your bar graph!
Try it yourself
- Show 17 with tally marks.
- In a tally chart, 4 bundles plus 2 strokes = ?
- A pictograph shows 1 star = 10 books. 6 stars = how many?
- From the fruit table above, how many more children like mango than apple?
- List 3 things in your day that can be collected as data.
- Draw a bar graph for: Monday 5 hrs, Tuesday 6 hrs, Wednesday 4 hrs, Thursday 7 hrs of study.
- Why is a bar graph easier to read than a long list of numbers?
Recap
- Data is information; we organise it into tables.
- Tally marks group counts in fives.
- Pictographs use pictures; bar graphs use bars.
- The tallest bar shows the biggest number , easy to spot!