Class 8 Mathematics

Chapters

1. 1Squares, Cubes and Their RootsLesson: Squares, Cubes and Their Roots · 15 sections · chapter quiz

   A gardener wants to plant 196 trees in a perfect square. How many trees go in each row? Squares and square roots answer this.

   • • I can find squares and cubes of numbers and recognise perfect squares and cubes.
   • • I can find square roots and cube roots using prime factorisation and patterns.
   • • I can use properties of squares (last digits, odd-number sums) to reason.
2. 2Power Play: ExponentsLesson: Power Play: Exponents · 15 sections · chapter quiz

   If you could fold a sheet of paper 46 times, its thickness would reach the Moon! Repeated doubling grows astonishingly fast, and exponents help us describe such growth.

   • • I can write repeated multiplication using exponents.
   • • I can use the laws of exponents, including zero and negative exponents.
   • • I can write very large and very small numbers in standard (scientific) form.
3. 3A Story of Numbers: Number Systems and BasesLesson: A Story of Numbers: Number Systems and Bases · 15 sections · chapter quiz

   Long ago, people counted with tally sticks, knots and pebbles. Over centuries the Indian place-value system with zero became the system used worldwide. How did that happen, and why does it work so well?

   • • I can describe how early number systems recorded numbers.
   • • I can explain place value as powers of a base.
   • • I can convert numbers between base 10 and other bases such as base 2 and base 5.
4. 4QuadrilateralsLesson: Quadrilaterals · 15 sections · chapter quiz

   A door, a kite, a tabletop and a road sign are all four-sided figures. What makes a square different from a rhombus or a rectangle? Their properties tell the story.

   • • I can classify quadrilaterals: parallelogram, rectangle, rhombus, square, trapezium and kite.
   • • I can use properties of sides, angles and diagonals of quadrilaterals.
   • • I can use the angle sum of 360° to find unknown angles.
5. 5Number Play: Divisibility and Digit PuzzlesLesson: Number Play: Divisibility and Digit Puzzles · 15 sections · chapter quiz

   Can you tell instantly whether 7,48,152 is divisible by 8, 9 or 11 without dividing? Divisibility rules — and the reasons behind them — let you do this.

   • • I can explain and use divisibility rules for 2, 3, 4, 5, 8, 9 and 11.
   • • I can reason about sums of consecutive numbers and multiples using algebra.
   • • I can solve digit (cryptarithm) puzzles logically.
6. 6We Distribute, Yet Things Multiply: Algebraic IdentitiesLesson: We Distribute, Yet Things Multiply: Algebraic Identities · 15 sections · chapter quiz

   How can you compute 103 × 97 in your head in seconds? An algebraic identity makes it easy: (100 + 3)(100 − 3) = 10,000 − 9 = 9,991.

   • • I can multiply algebraic expressions using the distributive property.
   • • I can use identities (a + b)², (a − b)² and (a + b)(a − b).
   • • I can use identities for quick mental calculations.
7. 7Proportional Reasoning – 1: RatiosLesson: Proportional Reasoning – 1: Ratios · 15 sections · chapter quiz

   When a photo is enlarged without stretching, its width and height grow in the same ratio. When you mix lemonade, the taste stays the same only if you keep the ratio of juice to water.

   • • I can write ratios and simplify them.
   • • I can recognise proportional relationships and solve problems with them.
   • • I can divide quantities in a ratio and convert units using ratios.
8. 8Fractions in Disguise: PercentagesLesson: Fractions in Disguise: Percentages · 15 sections · chapter quiz

   A shop offers 25% off, a test score is 18 out of 24, and a price rises by 10%. Percentages are fractions in disguise — fractions out of 100 — that make comparisons easy.

   • • I can convert between fractions, decimals and percentages.
   • • I can find a percentage of a quantity and express one quantity as a percentage of another.
   • • I can solve problems on percentage increase and decrease, discount, profit and loss.
9. 9The Baudhāyana–Pythagoras TheoremLesson: The Baudhāyana–Pythagoras Theorem · 15 sections · chapter quiz

   How can you make a perfect right angle with only a rope? Ancient Indian builders of fire altars described this in the Śulba-Sūtras, long before the result became known by Pythagoras's name.

   • • I can state the Baudhāyana–Pythagoras theorem for right-angled triangles.
   • • I can find an unknown side of a right triangle.
   • • I can test whether a triangle is right-angled and recognise Pythagorean triples.
10. 10Proportional Reasoning – 2: Maps, Shares and Inverse ProportionLesson: Proportional Reasoning – 2: Maps, Shares and Inverse Proportion · 15 sections · chapter quiz

    If 6 workers build a wall in 10 days, how long would 12 workers take? More workers mean fewer days — this is a different kind of proportion, called inverse proportion.

    • • I can use scale ratios on maps and models.
    • • I can work with ratios of three terms and divide a whole in a given ratio, including pie charts.
    • • I can recognise and solve inverse proportion problems.
11. 11Exploring Geometric Themes: Fractals and SolidsLesson: Exploring Geometric Themes: Fractals and Solids · 15 sections · chapter quiz

    Zoom in on a fern leaf or a cauliflower and each small part looks like the whole. Such patterns, called fractals, appear everywhere in nature. Solids, too, can be explored by unfolding and viewing them from different sides.

    • • I can describe self-similar patterns (fractals) and continue them step by step.
    • • I can visualise 3-D solids from their nets and 2-D views (front, side, top).
    • • I can use Euler's formula F + V − E = 2 for polyhedra.
12. 12Tales by Dots and Lines: Data HandlingLesson: Tales by Dots and Lines: Data Handling · 15 sections · chapter quiz

    Weather stations record temperature every hour; doctors track a child's height over years. Dots and lines on graphs turn these numbers into stories we can read.

    • • I can find and interpret the mean as a 'balancing point' of data.
    • • I can organise data into grouped frequency tables and draw histograms.
    • • I can choose and interpret dot plots, line graphs and other graphs.
13. 13Algebra Play: Number Tricks and PatternsLesson: Algebra Play: Number Tricks and Patterns · 15 sections · chapter quiz

    Think of a number, double it, add 10, halve it and subtract your original number. The answer is always 5! Why? Algebra reveals the secret of every such trick.

    • • I can use algebra to explain 'think of a number' tricks.
    • • I can use expressions in number pyramids and grids.
    • • I can use algebra to find the largest product and explain divisibility tricks.
14. 14Area of Plane FiguresLesson: Area of Plane Figures · 15 sections · chapter quiz

    A farmer's field is shaped like a trapezium. How can we find its area? By cutting and rearranging shapes cleverly, we can turn new shapes into ones we already understand.

    • • I can find areas of rectangles, squares, parallelograms and triangles.
    • • I can derive and use area formulas for trapeziums and rhombuses.
    • • I can find areas of composite shapes by splitting or rearranging them.