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CHAPTER AT A GLANCE
Finding Common Ground
•Unit: Number System
•Board weightage: Highest Common Factor, Least Common Multiple (the textbook says Lowest Common Multiple), prime factorisation and word problems on tiles, bags, bells and torans give regular 1-mark, 2-mark, 3-mark and 4-mark questions (please check the latest sample paper)
•Key ideas from the textbook: common factors and the greatest one, prime factorisation by the division method, factors as subparts of the prime factorisation, Highest Common Factor by minimum powers, common multiples and the smallest one, Lowest Common Multiple by maximum powers, product of two numbers = Highest Common Factor × Lowest Common Multiple
•Most scoring part: prime factorisation written neatly, then minimum powers for Highest Common Factor and maximum powers for Lowest Common Multiple
•Time to revise: about 70 minutes
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