CBSE Class 7 Mathematics Fractions Assignment Set 01

FRACTIONS

FILL IN THE BLANKS

Question 1. The reciprocal of 1 is _____ .
Answer: 1
In simple words: The reciprocal of a number is obtained by flipping its numerator and denominator. Since \(1 = \frac{1}{1}\), flipping it gives \(\frac{1}{1} = 1\).

Exam Tip: Remember that 1 and -1 are the only two numbers that are their own reciprocals.

Question 2. The number whose reciprocal does not exist is _____ .
Answer: 0
In simple words: The reciprocal of 0 would be \(\frac{1}{0}\), which is undefined because division by zero is not possible.

Exam Tip: Zero is the only rational number that does not have a multiplicative inverse (reciprocal).

Question 3. The product of the number with its multiplicative inverse is _____ .
Answer: 1
In simple words: Multiplying any non-zero number by its reciprocal always results in 1 (for example, \(\frac{a}{b} \times \frac{b}{a} = 1\)).

Exam Tip: This property defines what a multiplicative inverse or reciprocal is.

Question 4. If the number is greater than 1 then its reciprocal is _____ than 1.
Answer: less
In simple words: When you flip a fraction greater than 1 (like \(\frac{3}{2}\)), the result is a proper fraction less than 1 (like \(\frac{2}{3}\)).

Exam Tip: Reciprocals reverse inequalities for positive numbers: if \(x > 1\), then \(\frac{1}{x} < 1\).

Question 5. The reciprocal of _____ and _____ is the number itself.
Answer: 1, -1
In simple words: Only 1 and -1 give themselves when their numerators and denominators are interchanged.

Exam Tip: Be careful to include both positive 1 and negative 1 in your answer.

Question 6. Product of two fraction = Product of             
Product of             
Answer: Product of numerators / Product of denominators
In simple words: To multiply two fractions, multiply their top numbers together and their bottom numbers together.

Exam Tip: Remember the rule: Numerator times numerator over denominator times denominator.

Question 7.              \(\times \frac{3}{17} = 1\)
Answer: \(\frac{17}{3}\)
In simple words: To get a product of 1, multiply the fraction by its reciprocal, which is \(\frac{17}{3}\).

Exam Tip: A number multiplied by its reciprocal is always 1.

Question 8. \(5\frac{2}{3} \times\)              \(= 1\)
Answer: \(\frac{3}{17}\)
In simple words: First convert the mixed fraction \(5\frac{2}{3}\) into an improper fraction \(\frac{17}{3}\), then find its reciprocal, which is \(\frac{3}{17}\).

Exam Tip: Always convert mixed fractions to improper fractions before finding reciprocals or multiplying.

Question 9. \(\frac{1}{5} \div 9 = \frac{1}{5} \times \frac{1}{9}\) (T/F)
Answer: True
In simple words: Dividing by a number is the same as multiplying by its reciprocal. The reciprocal of 9 is \(\frac{1}{9}\).

Exam Tip: Division of fractions rule: Keep-Change-Flip (Keep the first fraction, change division to multiplication, flip the second fraction).

Question 10. \(\frac{13}{14} \div \frac{19}{17}\) Same as \(\frac{14}{13} \times \frac{19}{17}\) (T/F)
Answer: False
In simple words: When dividing by \(\frac{19}{17}\), you must multiply by its reciprocal \(\frac{17}{19}\), not \(\frac{14}{13}\). The correct expression is \(\frac{13}{14} \times \frac{17}{19}\).

Exam Tip: Only the second fraction gets flipped when changing division to multiplication.