Organisation of Data
To get the same information which Salma got, Ronald needs only a pen and a paper. He does not need pebbles. He also does not ask students to come and place the pebbles. He prepares the following table.
| Fruit | Mark | Count |
|---|---|---|
| Banana | ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ | |
| Orange | ✓ ✓ ✓ | |
| Apple | ✓ ✓ ✓ ✓ ✓ | |
| Guava | ✓ ✓ ✓ ✓ |
Do you understand Ronald’s table?
What does one (✓) mark indicate?
Four students preferred guava. How many (✓) marks are there against guava?
How many students were there in the class?
Discuss about these methods. Which is the best?
Which method is more useful when information from a much larger data is required?
Example 1 :
A teacher wants to know the choice of food of each student as part of the mid-day meal programme. The teacher assigns the task of collecting this information to Maria. Maria does so using a paper and a pencil. After arranging the choices in a column, she puts against a choice of food one (|) mark for every student making that choice.
| Choice | Number of students |
|---|---|
| Rice only | ||||||||||||||||| |
| Chapati only | ||||||||||||| |
| Both rice and chapati | |||||||||||||||||||| |
Umesh, after seeing the table suggested a better method to count the students. He asked Maria to organise the marks ( | ) in a group of ten.
| Choice | Number of students | Tally Marks |
|---|---|---|
| Rice only | ||
| Chapati only | ||
| Both rice and chapati |
Rajan made it simpler by asking her to make groups of five instead of ten using the mark ( | ).
| Choice | Number of students | Tally Marks |
|---|---|---|
| Rice only | ||
| Chapati only | ||
| Both rice and chapati |
Teacher suggested that the fifth mark in a group of five marks should be
used as a cross, as shown . These are tally marks. Thus,
shows the count to be five plus two (i.e. seven) and shows five plus five (i.e. ten).
| Choice | Number of students | Tally Marks |
|---|---|---|
| Rice only | ||
| Chapati only | ||
| Both rice and chapati |
Example 2 :
Ekta is asked to collect data for size of shoes of students in her Class VI. Her finding are recorded in the manner shown below :
5 4 7 5 6 7 6 5 6 6 5 4 5 6 8 7 4 6 5 6
4 6 5 7 6 7 5 7 6 4 8 7
Javed wanted to know (i) the size of shoes worn by the maximum number of students.
(ii) the size of shoes worn by the minimum number of students. Can you find this information?
Ekta prepared a table using tally marks
| Shoe size | Tally marks | Number of students |
|---|---|---|
| 4 | 5 | |
| 5 | 8 | |
| 6 | 10 | |
| 7 | 7 | |
| 8 | 2 |
Now the questions asked earlier could be answered easily.
You may also do some such activity in your class using tally marks.
Do this
- Collect information regarding the number of family members of your classmates and represent it in the form of a table. Find to which category most students belong.
| Number of family members | Tally marks | Number of students with that many family members |
|---|---|---|
Make a table and enter the data using tally marks. Find the number that appeared
(a) the minimum number of times?
(b) the maximum number of times?
(c) same number of times?