NCERT Class 4 Maths Chapter 14: Smart Charts

What are Smart Charts and Data Handling?

In our daily lives, we gather a lot of details. For example, if you ask 20 classmates about their favorite color, you will get 20 different answers. Writing them down in a long list can make it hard to tell which color is the most popular. This is where cbse class 4 smart charts come to our rescue! Data handling is the process of collecting, organizing, and representing information. We use tools like tally marks to count things fast. A tally mark is a simple vertical line '|' drawn for each item. When we reach five, we draw a diagonal line across the four lines to make a bundle of 5. This makes counting large numbers incredibly easy! By using smart charts, we can convert messy lists into clean, visual guides that anyone can understand instantly.

How to Draw Tally Marks Step-by-Step

1. Step 1: List the Categories — Write down the items or categories you are counting (e.g., Apple, Banana, Orange) in a clear column.
2. Step 2: Draw Vertical Lines — For each of the first four counts, draw a vertical line (|) next to the item. One line represents one item.
3. Step 3: Make a Bundle of Five — For the fifth count, do not draw another vertical line. Instead, draw a diagonal line across the first four lines. This completes a group of 5, resembling a neat little bundle.
4. Step 4: Continue Counting — For counts beyond five, start a new group next to the bundle. For example, 7 will be shown as one complete bundle of 5 and two single vertical lines (~~||||~~ ||).

Worked Examples: Reading Chapati Charts (Pie Charts)

• Example 1: Look at a circular 'Chapati Chart' representing a class of 40 students. If the circle is divided into exactly two halves, and one half represents children who love playing cricket, how many children love cricket?

  • Step 1: Identify the total number of children = 40.
  • Step 2: Look at the fraction representing cricket = Half (1/2).
  • Step 3: Calculate half of 40 = 40 ÷ 2 = 20.
  • Answer: 20 children love playing cricket.

• Example 2: A chapati chart shows that 1/4 of a class of 24 students like milk. How many students like milk?

  • Step 1: Identify the total number of students = 24.
  • Step 2: Look at the fraction representing milk = One-quarter (1/4).
  • Step 3: Calculate 1/4 of 24 = 24 ÷ 4 = 6.
  • Answer: 6 students like milk.

Exam Tip: Avoiding Common Mistakes with Tally Marks

A very common mistake students make in exams is drawing 5 vertical lines and then crossing them to make a group of 6. Remember: The diagonal line is the 5th line itself! To represent 5, you draw exactly 4 vertical lines and 1 diagonal line crossing them. Always recount your tally bundles to make sure they contain exactly 5 units each before writing the final totals.

Practice Questions with Solutions

• Q: Draw tally marks to represent the number 13.
  A: Step 1: We know that tally marks are grouped in bundles of 5.
  Step 2: Divide 13 into groups of 5. We get: 13 = 5 + 5 + 3.
  Step 3: Draw two full bundles of 5 and 3 individual vertical lines.
  Final answer: ~~||||~~ ~~||||~~ |||

• Q: In a class of 32 students, a chapati chart shows that 1/4 of the students like to eat apples. How many students do NOT like apples?
  A: Step 1: Find the total number of students = 32.
  Step 2: Calculate the number of students who like apples: 1/4 of 32 = 32 ÷ 4 = 8 students.
  Step 3: Subtract this from the total to find those who do not like apples: 32 - 8 = 24 students.
  Final answer: 24 students do not like apples.

• Q: Look at a bar chart where the bar for 'Burgers' rises to height 15 and the bar for 'Pizzas' rises to height 9. How many more children prefer Burgers to Pizzas?
  A: Step 1: Identify the preference for Burgers = 15.
  Step 2: Identify the preference for Pizzas = 9.
  Step 3: Subtract the smaller number from the larger number to find the difference: 15 - 9 = 6.
  Final answer: 6 more children prefer Burgers over Pizzas.

• Q: A group of 20 kids were asked about their favorite season. 10 kids said Summer, 5 said Winter, and 5 said Rainy. If you make a Chapati Chart, what fraction of the circle will represent Summer?
  A: Step 1: Identify the total number of kids = 20.
  Step 2: Note the kids who prefer Summer = 10.
  Step 3: Write it as a fraction: 10/20.
  Step 4: Simplify the fraction: 10/20 = 1/2 (Half).
  Final answer: 1/2 (or half) of the Chapati Chart represents Summer.

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