NCERT Class 4 Mathematics Math-Mela (Sanskrit): Chapter 13 — रहस्य-विन्यासः
This chapter, "रहस्य-विन्यासः" (Mystery Arrangement) from NCERT's Class 4 Mathematics textbook "Math-Mela", introduces students to multiplication concepts through engaging puzzles and activities. It uses a grid-based approach where students fill in missing numbers based on row and column products. The chapter emphasizes understanding multiplication by 10, representing it as "dasha" (tens), and converting it to hundreds. It also introduces the concept of breaking down multiplication problems into simpler parts, such as 5 x 15 being calculated as (5 x 10) + (5 x 5). This chapter aims to build a strong foundation in multiplication skills and problem-solving for CBSE students.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 4 |
| Subject | Mathematics |
| Book | Math-Mela (Sanskrit) |
| Chapter | Chapter 13 — रहस्य-विन्यासः |
| Language | Sanskrit |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 1 minute |
| Word count | 135 |
Learning outcomes
- Understand and solve multiplication puzzles using grids.
- Represent multiplication by 10 as tens and hundreds.
- Apply distributive property to solve multiplication problems (e.g., 5 x 15).
- Develop problem-solving skills through mathematical arrangements.
Vocabulary
| Word | Meaning |
|---|---|
| सङ्ख्याभिः | by numbers |
| फलानि | fruits (results/products) |
| अवशिष्टाः | remaining |
| उपयुक्तैः | suitable |
| गुणनं | multiplication |
| नारङ्गवर्णीयसञ्चिकायां | in the orange box |
| स्तम्भस्य | of the column |
| नीलवर्णीयसञ्चिकायां | in the blue box |
| गुणनफलं | product |
| रिक्तपेटिकां | empty box |
| समुचितसङ्ख्याः | appropriate numbers |
| दश | ten |
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Practice questions
- 2 × 10 = ? दश = ? Answer: 2 दश = 20
- 5 × 10 = ? दश = ? Answer: 5 दश = 50
- 8 × 10 = ? दश = ? Answer: 8 दश = 80
- 10 × 10 = ? दश = ? Answer: 10 दश = 100 (एकशतम्)
Frequently asked questions
What is the main topic of Chapter 13 of Math-Mela for Class 4?
Chapter 13, "रहस्य-विन्यासः", focuses on multiplication puzzles and understanding number arrangements.
How does the chapter explain multiplication by 10?
It explains multiplication by 10 as 'dasha' (tens) and shows how 10 tens make one hundred (100).
What strategy is used to solve larger multiplication problems like 5 x 15?
The chapter suggests breaking down the problem, for example, 5 x 15 can be solved as (5 x 10) + (5 x 5).
What kind of puzzles are included in this chapter?
The chapter includes grid puzzles where students fill in missing numbers based on given row and column products.
What is the significance of the orange and blue boxes in the puzzle?
The orange box shows the product for each row, and the blue box shows the product for each column, guiding the student to find the missing numbers.
Related resources
Important topics
Topics covered
NCERT Class 4 Mathematics — Math-Mela (Sanskrit) — Chapter 13 — रहस्य-विन्यासः. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.