NCERT Ganita Prakash, Class 8, textbook pages 103–134 (Part 2)

How to teach Class 8 Maths Part 2 Chapter 5, Tales by Dots and Lines, at home

Data: mean, median and graphs, taught with things you already have at home: a 30-minute activity, a game for the week, a 5-day plan and the mistakes to watch for.

120130140150160170

NCERT Class 8 Maths Part 2 Chapter 5 Tales by Dots and Lines: what it teaches

Your child revisits mean and median, sees the mean as a balance point, groups data into class intervals, and reads and draws graphs like histograms and line graphs to tell a story from data.

Why it matters later. Data handling leads to statistics in Class 9–10 and data science.

See it: this chapter in pictures

10, 12, 14, 16sum 52 ÷ 4mean = 13
Mean is the balance point.
2, 5, 8, 9middle two: 5 and 8median = 6.5
Average the middle two.
120130140150160170
Histogram bars touch because intervals are continuous.

You need

  • squared paper
  • a set of family or class data
  • a calculator

Tonight’s 30 minutes

  1. Find the mean of test scores and check it balances: total distance above equals below.
  2. Group heights into intervals like 120–130 cm.
  3. Draw a histogram of the grouped data.
  4. Tell a story from a line graph of temperatures.

Words to use

  • mean
  • median
  • class interval
  • frequency
  • histogram
  • line graph

Watch for

  • Gaps between histogram bars. Histogram bars touch because intervals are continuous.
  • Overlapping intervals. Use 120–130, 130–140 with a clear rule for 130.

What it sounds like at home

A short example of the conversation. Your words will differ; the questions are what matter.

YouMedian of 5, 8, 2, 9?

Your childOrder: 2, 5, 8, 9. Middle two average: 6.5.

A game for this week: Data detective

  1. Collect 20 data points (like heights or times).
  2. Group them and draw a histogram.
  3. Find mean and median.
  4. Tell one surprising story.

A 5-day plan, 30 minutes a day

  1. Day 1Mean as balance.
  2. Day 2Class intervals.
  3. Day 3Histograms.
  4. Day 4Line graph stories.
  5. Day 5Data detective.

Everyday moments to practise

  • Health charts.
  • Sports statistics.
  • Weather reports.
  • Election results.

Quick check

Ask these at the end of the week. Tap to see the answer.

Mean of 10, 12, 14, 16?

13.

Median of 5, 8, 2, 9?

6.5.

Why do histogram bars touch?

Intervals are continuous.

Ready for the next chapter when your child…

  • Finds mean and median.
  • Groups data.
  • Draws and reads histograms.

Activities, wording and illustrations are Mathify Kids’ own, following the topics of NCERT’s Ganita Prakash (Class 8). See the full Class 8 parent guide for every chapter.

Questions parents ask

Why is the mean a balance point?

Values above and below it balance out.

What is a histogram?

A bar graph for grouped data with touching bars.

How do I choose class intervals?

Equal widths that cover all data, usually 5–10 groups.