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CHAPTER AT A GLANCE
Number Play
•Unit: Number System and Patterns
•Board weightage: Parity (even and odd), expressions for even and odd numbers, magic squares and the Virahāṅka-Fibonacci sequence give regular 1-mark, 2-mark and 3-mark questions (please check the latest sample paper)
•Key ideas from the textbook: sums and differences of even and odd numbers, parity, algebraic expressions that are always even or odd, nth even and odd number, sums in a grid, magic squares (magic sum 15, centre 5), Chautīsā Yantra, Virahāṅka-Fibonacci numbers
•Most scoring part: giving a reason using parity, and finding the magic sum and the centre of a magic square
•Time to revise: about 50 minutes
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