Kerala SCERT · Mathematics Part 1 · Standard IX · Chapter 4

Multiplication Identities ഗുണനസമവാക്യങ്ങൾ

How a rectangle cut into pieces explains (x + y)(u + v), how the same idea turns 26 × 17 into a mental sum, and how algebra proves calendar tricks, digit-reversal puzzles and multiplication-table patterns. An interactive, animated self-study guide: the basics from earlier classes, every idea of the chapter with real-life uses, animated solutions to every textbook question, a revision sheet, and a model test with a fully solved paper.

How to use this guide

🎬 Watch the animations

Every idea has a step-by-step animation. Press Next ▶ to move one step at a time, or ▶▶ Auto play to watch it like a video. You can go back any time.

🖐️ Play with the numbers

Sliders change the numbers in every picture. Seeing the four pieces of a rectangle change together is the fastest way to feel why an identity is true.

✍️ Try before you see

Questions come with a Show answer button. Always attempt the question in your notebook first, then check. The quizzes give instant feedback.

📖 Textbook links

Purple മലയാളം words are the exact terms used in your textbook, so you can match every page here with the book (pages 61–82).

Learning path

Follow the pages in order. If you are comfortable with the distributive law, letters in algebra and the Class 8 identities, you may skim pages 1–4, but do try their quizzes.

Part A · Build the foundation (nothing assumed)
Part B · The chapter, idea by idea
Part C · Use it, revise it, test yourself

The chapter in one picture

▦ A rectangle cut into four: (x + y)(u + v) = xu + xv + yu + yv

Change the four numbers. The big rectangle is (x + y) wide and (u + v) tall, so its area is the product of the two sums. Cutting it along the dotted lines gives four smaller rectangles whose areas are the four products. That one picture is the whole chapter: everything else is this idea used cleverly.

Quick glossary (Malayalam ↔ English)

Textbook termEnglishMeaning
ഗുണനസമവാക്യംMultiplication identityA rule for a product that is true for every choice of numbers
സർവസമവാക്യംIdentityAn equation that holds for ALL values of the letters
തുക / വ്യത്യാസംSum / differencex + y / x − y
ഗുണനഫലംProductThe result of multiplying
പരപ്പളവ് / ചുറ്റളവ്Area / perimeterlength × breadth / 2(length + breadth)
എണ്ണൽസംഖ്യNatural number1, 2, 3, …
ഒറ്റസംഖ്യ / ഇരട്ടസംഖ്യOdd / even number2n + 1 / 2n
അടുത്തടുത്ത സംഖ്യകൾConsecutive numbersx, x + 1, x + 2, …
ശിഷ്ടം (മിച്ചം)RemainderWhat is left after division, e.g. 3n + 1 leaves 1 on ÷ 3
രണ്ടക്കസംഖ്യTwo-digit number10m + n with digits m and n
ഗുണിതപ്പട്ടികMultiplication tableRow m, column n holds mn
ക്രിയാകൗതുകങ്ങൾCuriosities of operationsNumber tricks explained by algebra

Made for self-learning. Works offline – every page is a single file. Study material prepared by Claude for Madhu's family study folder, October 2026.