Q1
1/2 + 1/4 equals:
A3/4
B2/6
C1/6
D2/4 (unsimplified, still 1/2)
CBSEClass 8 (CBSE)MathematicsCh 3 · Topic 2
Operations on Rational Numbers
Learning to add, subtract, multiply and divide rational numbers.
Core concept
Special care must be taken with negative rational numbers, applying the same sign rules used for integers: multiplying or dividing two rational numbers with the same sign gives a positive result, while different signs give a negative result. For example, multiplying -2/3 by 3/5 gives -6/15, which simplifies to -2/5, following both the fraction multiplication rule and the negative-sign rule together.
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CBSE class 8 operations on rational numbers
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• Rational number operations follow the same rules as fraction operations.
• Common denominators are needed for addition/subtraction with different denominators.
• Sign rules for integers also apply: same signs give positive results, different signs give negative results.
• Example: -2/3 x 3/5 = -6/15 = -2/5 (simplified).