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📗 Class 7 maths · session 3 of 12 · 60 minutes · 🎁 free with an account

Data handling

Welcome to the Data Control Room! Captain Calc needs your help to organize superhero test scores and predict upcoming mission outcomes.

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🤖 Written with Google's Gemini AI. A second AI solved all 55 questions without seeing the answers, and both agree. One of our teachers has not read it yet, so if something looks wrong, please tell us.

A complete lesson · 60 minutes

Teach it, see it, practise it, all on this page.

Open this page with your learner and work down it, or press Teach this lesson to go through it one step at a time on a big screen. Every section has something to do.

🎁 Unlock free with an accountRead part 1 free
  1. Warm-up3 min
  2. Warm-up games5 min
  3. Mean and Range of Data8 min
  4. Mode of Data7 min
  5. Median of Data7 min
  6. Chance and Probability7 min
  7. Hero Score Analyzer6 min
  8. Probability Patrol5 min
  9. Data Master Challenge6 min
  10. Quiz5 min
  11. Set the project1 min

By the end you can

  • Calculate the arithmetic mean and range of a given dataset.
  • Find the mode and median of raw data.
  • Understand frequency and construct simple tally counts.
  • Determine the probability of simple events using fractions.

Before you start

  • Basic addition, subtraction, multiplication, and division of whole numbers.
  • Understanding simple fractions in lowest terms.

Have ready

  • Notebook and pen
  • Ruler

Class 7 · CBSE, ICSE and state boards

Warm-up · think first

Captain Calc scored 12, 15, and 18 points in three training rounds. What is his average score per round?

Show the answer

15. Add all three scores to get 45, then divide by the total number of rounds: 45 ÷ 3 = 15.

Teacher tip: Ask students if anyone used mental math to spot the middle number since the scores increase by equal steps.

More warm-ups for every class →

🎮 Warm-up games · 5 quick games

Play with Captain Calc

Six minutes with Captain Calc. Vote, say why, then show the answer.

  1. Which one of these numbers cannot be the probability of an event? (0 · 1/2 · 5/4 · 1)
    Answer: 5/4. The probability of any event must be between 0 and 1 inclusive. A fraction greater than 1 like 5/4 cannot represent a probability.
  2. Would you rather calculate the mean of 5 large numbers or find the mode of 20 small numbers? (A: Mean of 5 large numbers · B: Mode of 20 small numbers)
    Answer: Both choices build great skills! Option A requires careful addition and division, while Option B relies on accurate counting and tracking frequency.
  3. The mode of a group of numbers is one of the numbers in the data. (Always · Sometimes · Never)
    Answer: Always. The mode is defined as the observation that appears most frequently in the dataset, so it must be one of the original numbers.
  4. The mean of four numbers is 10. Three of the numbers are 7, 9, and 12. What is the fourth number?
    Answer: 12. The total sum must be 4 × 10 = 40. The sum of the three given numbers is 7 + 9 + 12 = 28. Subtracting 28 from 40 gives the fourth number: 40 - 28 = 12.
  5. Why might a shop owner care more about the mode of shoe sizes sold rather than the mean shoe size?
    Answer: The mode shows which shoe size is sold most frequently so the shopkeeper knows which exact size to restock most. The mean size could end up as a decimal like 7.4, which is not an actual shoe size.

Part 1 of 4 · learn, see, practise

Mean and Range of Data

Data is a collection of numbers gathered to give information.

The arithmetic mean is calculated by dividing the sum of all values by the total number of values.

The range is the difference between the highest value and the lowest value in the dataset.

Example 1

Find the mean and range of Rohan's test marks: 40, 50, 30, 60, 70.

  1. Sum of values = 40 + 50 + 30 + 60 + 70 = 250.
  2. Total number of marks = 5.
  3. Mean = 250 ÷ 5 = 50.
  4. Highest value = 70 and Lowest value = 30. Range = 70 - 30 = 40.

Answer: Mean = 50, Range = 40

Example 2

The heights of 5 superhero recruits in cm are 142, 148, 135, 150, 145. Calculate the mean height.

  1. Sum of heights = 142 + 148 + 135 + 150 + 145 = 720.
  2. Number of recruits = 5.
  3. Mean height = 720 ÷ 5 = 144 cm.

Answer: 144

Practise it

Start with the warm-up and go as far as you can. The stretch questions are meant to be hard.

Warm-up

Warm-up

Core

Core

Stretch 🔥

Stretch 🔥

Answers (for the teacher)
  1. 10
  2. 22
  3. 60
  4. 3
  5. 30
  6. 9

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Unlocking the rest of this lesson gives you:

  • Part 2: Mode of Data, with practice at three levels
  • Part 3: Median of Data, with practice at three levels
  • Part 4: Chance and Probability, with practice at three levels
  • Class activity 1: Hero Score Analyzer
  • Class activity 2: Probability Patrol
  • Class activity 3: Data Master Challenge
  • A 10-question quiz
  • After-class project: Daily Weather and Activity Tracker
  • Homework and a printable practice sheet with answers
  • Teach mode and the minute-by-minute teacher's plan
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FAQ

Data handling: questions

What is the main difference between mean, median, and mode?

Mean is the calculated average value, median is the middle value when sorted, and mode is the value that occurs most frequently.

Why can a dataset have more than one mode?

If two or more numbers tie for the highest frequency, each of those numbers is considered a valid mode of the dataset.

Can probability be written as a decimal or percentage?

Yes, probability can be expressed as a fraction, a decimal from 0 to 1, or a percentage from 0% to 100%.

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